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DISCOVERIES IN EMBRYOLOGY.
58
certain number will still be devoted to the defence of the empire ; but DISCOVERIES IN EMBRYOLOGY. BY not one will be thrown away, and the cost JOHN MILLER, be will always counted, not in money only, MECHANIC. but in blood and breath. So, likewise, if low dietaries are found fatal to the inmates TIIE letter which I sent to your Jourof workhouses, though these asylums of the i dated Nov. 25th, last, for insertion, wretched be made tests of destitution, the addressed to M. Coste and Mr. Owen, with Guardians will not push the rigour of their a view to have determined, from preparations made by themselves, the following system inconsiderately far. They will not points, has remained unnoticed, notwithhurry precipitately forward, by looking at standing I have given them five weeksto the economy, and believing that every ounce reply, and also sent a letter to each by post. I therefore now, agreeably to my promise, of food which they save is a gain to the fast- forward to you the drawings of my preparayou will ing paupers. They will know that food is tions therein referred to. I hope examine the preparations, lest any one blood, that blood is life ; and that the pri- should doubt their genuineness, and dispute vation of food is the privation of life. This the truths which they teach, since I am poor, conviction will temper the severity of the and the two parties opposed to me are great authorities. The two preparations which I period of transition. have selected from my series are one of Hence, serious blame attaches to the the human ovum and one of the cat, and both engravings which accompany this Poor-Law Commissioners, for sending forth, paper are of the size of nature.If I had at the very outset of their career, ignorant given smaller dissections the existence of might have been disputed. The partisans, to persuade the Guardians that the vessels I have adopted is, to make three dissecplan the lowest dietaries are decidedly condu- tions of each animal, varying in the differcive to health,-a doctrine which we be- ent stages of impregnation from eight to lieve is entirely false, which is opposed to thirty days; and I preserve the duct, or the artery or vein, distinct, so that they are, as the common sense of the country, and which it were, so many links in a chain. The has not an iota of substantial evidence to points under consideration are involved in the following questions :adduce in its favour. If it be true that does the duct from the ve-
liament,
a
nal,
First,-Where
scanty food is
and increases sicula umbilicalis in the kangaroo, and in cut down the herbivorous and carnivorous animals, termithe will Guardians mortality, nate in the intestinal canal ? dietaries with regret and slow deliberaSecond,—Where do the omphalo-mesention ; the consequences wi!l stare their con- teric artery and vein commence and terminate in both classes of animal ? sciences in the face. If they believe-and The vesicula umbilicalis, or vesicula the doctrine has been incessantly preached alba, or blastoderm, was known to Wm. in their ears-that when they lower the rates Hunter;he had even seen the duct filled with the same kind of fluid as the alimenand the dietaries they invigorate the sinews tary canal, but connected with it by an imof the pauper, the deterioration of the work- pervious thread. In the ninth edition of Burn’s " Mid. house diet may be expected to proceed in a wifery," p. 219, the blastoderm, or vesicula rapid progression. Liberal men, like Lord umbilicalis, is seen " entering the caudal RADNOR, when imbued with the fictitiousextremity by a short pedicle:’ In No. 597 of THE LANCET, p. 1029, Dr. belief that the " dyspepsia of the poor" is; states as follows :-" That on the " Grant simply caused by overfeeding," and that intestine of the newly-hatched and small the abstraction of butcher’s meat has " an even the mature bird, a minute coccal appeneffect altogether miraculous," in preventing dix is left in the situation where the yolkdisease, will rejoice to see the wages of the bag formerly opened into the alimentary labourer with a large family reduced to canal; this I have also seen on a correof the small intestine in the seven shillings a week, and they will regret sponding part human foetus." to see his condition ameliorated, when that " The duct terminating in the middle of amelioration places the insidious poison of the small intestines."—Burdoch. " Into the coecum."—Oken. « By a neck with the in. English beef within his reach. a
punishment,
59
testinal canal."—Bojenus. Breschet, Sallor, below, admits of a ready transmission of Woulf, and Beer, do not specify in what the fluid into it. Hence the whole intespart the duct terminates. Velpean states tinal canal is no more than an elongation of that he
canal,
pressed the fluid in the duct into the the dnct; specify where the dissected
but he does not
so
that if the intestinal canal be
out of the germ, it resembles the " The duct 1ermi. tendril of a vine, and is not like an open
duct itself terminated. nates at the lower part of the ileum."—
vessel, or gutter, as some authors have represented. There is great difficulty in disThe description of the termination of the tinguishing, during the first six weeks, what duct by Mr. Mayo, is the most remarkable is duct, or duodenum, jejunum, ileum, or of all. In his fourth edition, p. t2l, he cœcum, in the embryo. No person has yet thus writes: In a remarkable specimen given the measurement of the duct, and this belonging to Mr. Sweatman, the connection is a point which it is most important to of the vesicula alba with the alimentary know. In the human ovulum, and in the canal is beautifully shown. The vesicula cow, in both of which the same period of lies immediately without the amnios ; the gestation is occupied, the duct is always at whole length of the thread leading from it least six lines in length. This duct is first is an inch and a quarter; the length of the absorbed at its point of junction with the umbilical chord is 22-50ths of an inch; the vesicula umbilicalis. In the ovulum of the vessel is pear-shaped, 11-50ths of an inch cow the duct is pervious at thirty days, and in its long diameter, 8-50ths across. The at six weeks it disappears, all except the filament of the vessel joins the duodenum, remnant which is attached to the canal (inclose upon what seems the pylorus, or at testinal). This I prove by the date of copuMeckel.
about I.80th of an inch from it. It is sup- lation in this animal. posed that the embryo was about two months The length of the intestinal canal, as corai. old at the period of the sudden death of the pared with that of the body, is greater in mother." the foetrrs and in infants than in adults. It Now, Mr. Sweatman had seen a part of is generally longer, in proportion to the the series of my preparations, in which the body, in herbivorous than in carnivorous terminations of the omphalo-mesenteric ar- animals. The rule, however, has many extery and vein are shown. Subsequently, in ceptions; in the sloth, though herbivorous, a conversation with that gentleman, I re- the intestinal canal is scarcely as long as marked that I was amazed to hear him the body, while in the seal, which is carnideclare that the duct terminated in the duo- vorous, it is thirty times as long, The rat denum, and asked him if his specimen show- and mouse being omnivorous, have an intesed the omphalo-mesenteric artery and vein, tinal canal three times the length of their and where the vein terminated ; if the vessel bodies respectively; man seven times; the noted by him was the duct? To this he hog thirteen times. I believe that no anicould make no reply, but gave me the names mal but man and the ourang outang has of eight eminent authorities in London, who both a coecum and an appendix vermihad examined the specimen. I told him formis. that if the conclusions of these eight men M. Serres states that the lateral halves of were the same as his own, they were all in- the body are developed apart from each correct. He also stated that Mr. Owen had other, and afterwards coalesce. I must examined the specimen. I observed that differ from this authority, for I have dissecttrnth required no support from authority, ed the duct out of the human germ, and find but stood upon its own basis. He asked that there is no perceptible difference in me why I was so positive in my statement, thickness throughout its whole extent. I not having seen his specimen. I rejoined, have preparations showing the duct and the that the astronomer predicts the eclipse of omphalo-mesenteric artery and vein, all the sun long before its occurrence ; why, three dissected quite to the germ, but the then, should not the physiologist tell the parts are not fully developed, and might be formation of each organ as it proceeds to- disputed.* wards perfection ? Mr. Sweatman invited me to see the spe* From the preceding descriptions it is cimen, but not until it was put up in the bottle. I inquired why I was not among apparent that I cannot concur with M. the eight authorities who examined it, after Serres in the statement that the development I had studied embryology as I have done, of the embryotic animal is from the surface for so many years, and he visiting me very of its two lateral halves, towards the mesial often, and seeing my preparations. Alas ! line. The instance adduced will show that I am a poor mechanic, the law which he wishes to- establish is not of universal application. At a future Termination of the Duct, proceeding from the probably in my forthcoming publicaVesicrclce Umbilicalis, in the Germ, tion, I shall advert to the formation of the The duct from the vesicula umbilicalis uterus and the bladder, as affording further shoots into the germ, which, being always evidence against M.Serres’ views. -
period,
60
yolk- the ileum in the mammalia, which fact was in general, is in the coecum. observed by Meckel, who is the only phy. In most birds there is no caecal valve, and siologist, out of thirteen authorities whom I in many there is no coecum, consequently have named, that nearly approaches the the duct must terminate in another part of truth. The remnant of the duct in the kan. the canal, as is the case with those ovivipa- garoo, in my series of preparations, is in the InI middle of the appendix vermiformis, analo. rous animals which have no coecum. sharks I have found the duct gous with what is shown in the engraving0 of above, but close to, the valve. The duct the cat. terminates sometimes at the lower part The termination of the duct of the
bag
in
birds,
of
terminate
Human OCMM a.
atfii-st Week.
Flocculent chorion.
b. Chorion membrane. !;.
Amnion membrane.
d. Stomach. e.
Duodenum.
f. Vesicula umbilicalis.
g.
Separation of the
oiriphalo-mesenteric
vein and artery. le. vein accidentally in the dissection. ruptured
Omphalo-mesenteric
i. Omphalo-mesenteric artery. k. Urachus communicating with
bladder. 1. The umbilical chord.
the
61
Duodenum. f. Appendix vermiformia. g. Remainder of the duct from the vffuumbilicalis.
Fœtus of the Cat at the sixth Week. a. Alantois. b. Urachns bladder.
e.
i thecula ,
communicating with
d. Stomach.
h.
’i
i.
Omphalo-mesenteric vein. Omphalo-mesenteric artery.
in the germ, and that the vesicula umbili. calis receives them ; this is incorrect. The omphalo-mesenteric artery and vein are formed upon the surface of the vesicula, shoot alongside of the duct, into the the artery terminating in the anterior small branches of the mesentery of the their origin or their termination. In BresIn the whole course of my dissecchet’s work the same omission is observ- tions I have only once found the artery terable ; hence I imagine, that if these au- minating posteriorly, and that was in a thors had preparations, showing the fact, human embryo. The mesenteric arteries of them would have appeared in proceed towards the vena portaR ; the vein engravings their works. Pockels states that the om- enters another vein of the duodenum, near
Termination of the
O)nphalo-Illesenteric Artery and Vein. Wrisberg, in 1764, gives the best drawing of this, but says that the bifurcation is pretended. In Velpeau’s work there are eight plates of the vessels, but none of them show
phalo-mesenteric artery and vein are formed
and germ, ileum.
the
pylorus; the veins of the intestines run
62
the small quantity of the vitellus the ovum in the ovary contains, dis. which portæ.* the first few days, and is appears The first Circulation in the Embryo. consumed in the rapid formation of the vesi. The blood is first seen on the surface of cula umbilicalis membrane. the vesicula umbilicalis, or blastoderm. Second; The fluid contained in the vesiThe blood-vessels proceed from its surface cula umbilicalis is a secretion, and not a with the duct, into the germ. If analogy nutrient fluid, because the quantity in. derived from the cow can be admitted in creases rather than diminishes during the reasoning on the human species, blood- early development of the embryo. vessels are seen on the 18th day; and the Third,-As the embryo becomes developheart is not formed complete until the 30th ed a small portion of the blastoderm memday, so that the circulation is performed as brane is found attached to the intestine by in some of the lower animals which have no a very small pedicle, of which the greater hearts. The views of Professor Alison, re- portion is on the outside of the belly. garding the self-moving power in the blood, Fourth,—In the rabbit this vessel is very are beautifully borne out by the first circu- considerable, and the embryo, whose abdolation of the germ, if it be admitted that men is turned towards it, is sunk in a desuch a power exists at all in the blood. I pressed line in the vessel, and this becomes, believe this to be the first time that the by degrees, inclosed in a double bag, simiorigin and termination of those vessels has lar to that which is formed by a double been explained. nightcap on the head. This development of In M. Coste’s " Memoir," 1834, the fol- the embryo is only in the rodentia. Fifth,-That the embryo of the other mamlowing statements are found:— First; That the ovum of the rabbit is malia has a different origin. completely free from adherence to the uterus Sixth,—On the ninth day we also begin for the first nine or ten days ; that the nutri- to see the omphalo-mesenteric vessels passtion which the embryo receives is derived ing from each side of the embryo to the from the fluids secreted by the uterus, be- inner surface of the invaginated vessel._________________________________ (LANCET, No. 628). * These vessels go to form the first porWhile reviewing those statements from tion of the vascular system of the foetus, M. Coste’s "Memoir," I beg attention to the which is the vena portae, which terminates following observations :in the liver. This will serve to explain the First,-That the vesicula umbilicalis is great size of that viscus before the heart is formed in the ovary, and not in the uterus; formed; and it is well known that the um- and that the vitellus which it contains does bilical vein from the placenta, in the second not form the membrane. circulation, terminates in that organ also. Second,—That the embryo derives its The great size of the liver in the foetus has whole nutrition from the vesicula umbilicaattracted the notice of physiologists in all lis. The vesicula is four or five times larger ages, and various conjectures have been than the germ, when first visible, and the offered to explain that phenomenon. Dr. vitellus diminishes as the development of Robert Lee, in the " Philosophical Trans- the germ proceeds. actions"for 1829, attempts to show that the Third,—M. Coste does not specify in liver is an organ which secretes albumen what portion of the intestinal canal the duct during foetal existence, and forms albumen terminates. This point will be found clearfor the nourishment of the foetus. The ed up in a former part of this paper. Doctor’s ideas must be imaginative, and not Fourth,—That the vesicula umbilicalis in deduced from facts; as he thus maintains the rabbit is three lines in length, and one that the organ performs two functions, and a half in breadth. Instead of the vesinaraely, that of secreting albumen before, cula umbilicalis being larger in the rabbit and bile immediately after, the birth of the it is smaller. child. The difference between albumen and Fifth,—There is no difference in the g;erbile is as great as between any two secre- minal origin of the rabbit and the other tions of the body. I have dissected 135 mammalia. Sixth,—M. Coste does not point out either embryos and foetuses, and have never found albumen in the gall-bladder, but a consider- the commencement or the termination of the able quantity of gall is universally found omphalo-mesenteric artery and vein, the in the cystic bag during the whole period of description of which I have likewise forfoetal existence. If the liver be an organ merly given. Would it be believed that a man who had which secretes albumen for the nourishment of the foetus, I would ask Dr’. Lee to ex- been studying embryology during eight plain the source of nutrition in those cases years could, on the presentation of such a in which the liver is wanting. There are Memoir, obtain from the Institute of France many such on record ; that of Dr. Clarke, a gold medal ? Where are the preparations " Phil. Trans." 1793 ; and that of Sir B. that accompanied, or ought to accompanied the Memoir? . Is ihere-none to illusBrodie, 11 Phi!. Trans." 1809, are
into the
meseraic, which
go to the
vena
cause
instances,
have
63
trate the points advanced? or has the author not know in what species of rats Mr. Owen no other support for his views than the ima- found this large vesicula umbilicalis ; but I ginary ideas of a man who never studied the have preparations of the sow showing the book of nature ? If lie really possess proofs vesicula eight times larger than the vesicula I fear that he has only mutilated what he in rats which I have dissected; and he like. had seen, for he never could have commit- wise states that the vessel is more perenanent in rats than in other animals. The preted such errors to paper. That the embryo of a rabbit sinks into the parations of the human placenta in my vesicula umbilicalis, and forms a double series show the vesicula with the omphalobag, similar to a nightcap, is an anomaly mesenteric artery and vein at the ninth The truth is, month ; which is denied by Velpeau and all never to be found in nature. that M. Coste never has seen the vesicula authorities; and I could convince Mr. Owen umbilicalis in the rabbit, for the vesicula is that it is more permanent in the human subonly three lines in length, and one and a ject than in animals. What resemblance the half in breadth. No doubt the vesicula in ovum of rats bears to that of kangaroos, and the kangaroo was a wonder to him, for he the ovum of kangaroos to that of birds, it is has never seen it in any other animal, not not for me to say. I will leave Mr. Owen to even in a rabbit, but represents the alantois illustrate that point; but if any analogy obfor that vessel. tains, the viviparous should be compared The preparation above described was ex- with the oviviparous, and not with the ovihibited on August the 22nd, 1837, at the parous, which all authors on embryology have done. It is now many years since I Zoological Society. Mr. Owen’s paper read before the Royal demonstrated by preparations that the emSociety in London, in 1834, has also attracted bryo of all animals is nourished by a vesiduring the last three years a considerable cula umbilicalis, or yolk-bag, such as the share of attention in Britain, as well as on oviviparous, and not by an alantois, as has the Continent, amongst physiologists,—the been represented by M. Coste and Mr. exhibition of a foetus o-f a kangaroo and its Owen,-the one to the Royal Institute of membranes, at the middle period of gesta- France, the other to the Royal Society of tion, which in that animal lasts 38 or 39 London, the papers respectively being read days, being a novelty in comparative ana- in 1834. That these gentlemen are not tomy. The appearances described were themselves very well satisfied with their found on about the 20th day after impreg- vaunted discoveries, I collect from the fact, nation, when, he states, ‘there was no pla- that they have both lately, in 1837, ancental structure, nor villi, nor the appear- nounced to the Academy of Science in Paris ance of vessels in the uterus nor the chorion." the discovery of another vesicula umbilicaNow, if the reader will examine the uterus lis in the kangaroo ; and M. Coste makes of a mare, or a sow, he will find precisely mention of the name of Mr. Owen in the disthe same appearance at the same date after covery, but Mr. Owen never adverts to that copulation, up to the fifth week, in both ani- of M. Coste. I have little doubt that before mals, and the same appearance on the foetal 1839 they will discover another, as all the membranes. It is during this period in world knows that they are both men of those animals which go longer than five "great scientific research," and physiology months in utero-gestation, that the embryo is greatly indebted to them for their discois supported or nourished by the omphalo- veries. JonN MILLER, JOHN MiLLER, Mechanic. mesenteric vessels, from the vesicula umbi1838. March, 1838. licalis, and not from the vascular membrane 3, Theobald’s-road, March, or sac, which is the alantois. Hence I doubt whether Mr. Owen ever saw the vesicula VIBRATORY CYLINDERS RECENTLY umbilicalis, or he never would have so inDESCRIBED BY HENLE* correctly represented for it, tlae cclarrtois; and HENLE scraped a little mucus frorn the it is somewhat singular that Mr. plaeed it under the should perpetuate the same error as I have bodies, nearlv cylindrical in of M. the conduct previously exposed of the form of incisor of considerable
3, Theobald’s-road,
Owen larynx ofa frog, and
rnicooscope, when
Coste.
size,
were
teeth, seen revolvingslowly.while small
London’s "Mag. of Nat. Hist.," 1837, it. vesicula umbilicalis, butthathe did11 thenot know vesicula He likewise of theofcylm. extremity in a fringe cilia, apparent along the;larger it laypresents fine umbilicalis is largest in the glires, came der. long body, cylinder exhiThe which is next to themarsupiata, and nucleus, and surmounted by bits a striking affinityto birds,&c." I do containing in the stomach and intestines cilia cilia ;
in moved about in every direction; In Owen describes the two sacs, and the globules Mr. a few minutes all became still. But before pyriform sac he calls the alantois. It is the motion ceased, the cause of the motion be-
declares
order
a
a
but
the mouth the long cylinare wanting; is flattened into a polyedric body in
’ M. Coste saw the vesicula in the kandrical garoo with Mr. Owen, in London, 1837. No. 742. See LANCET,
!
* In
an
Inaugural Thesis.
certain number will still be devoted to the defence of the empire ; but DISCOVERIES IN EMBRYOLOGY. BY not one will be thrown away, and the cost JOHN MILLER, be will always counted, not in money only, MECHANIC. but in blood and breath. So, likewise, if low dietaries are found fatal to the inmates TIIE letter which I sent to your Jourof workhouses, though these asylums of the i dated Nov. 25th, last, for insertion, wretched be made tests of destitution, the addressed to M. Coste and Mr. Owen, with Guardians will not push the rigour of their a view to have determined, from preparations made by themselves, the following system inconsiderately far. They will not points, has remained unnoticed, notwithhurry precipitately forward, by looking at standing I have given them five weeksto the economy, and believing that every ounce reply, and also sent a letter to each by post. I therefore now, agreeably to my promise, of food which they save is a gain to the fast- forward to you the drawings of my preparayou will ing paupers. They will know that food is tions therein referred to. I hope examine the preparations, lest any one blood, that blood is life ; and that the pri- should doubt their genuineness, and dispute vation of food is the privation of life. This the truths which they teach, since I am poor, conviction will temper the severity of the and the two parties opposed to me are great authorities. The two preparations which I period of transition. have selected from my series are one of Hence, serious blame attaches to the the human ovum and one of the cat, and both engravings which accompany this Poor-Law Commissioners, for sending forth, paper are of the size of nature.If I had at the very outset of their career, ignorant given smaller dissections the existence of might have been disputed. The partisans, to persuade the Guardians that the vessels I have adopted is, to make three dissecplan the lowest dietaries are decidedly condu- tions of each animal, varying in the differcive to health,-a doctrine which we be- ent stages of impregnation from eight to lieve is entirely false, which is opposed to thirty days; and I preserve the duct, or the artery or vein, distinct, so that they are, as the common sense of the country, and which it were, so many links in a chain. The has not an iota of substantial evidence to points under consideration are involved in the following questions :adduce in its favour. If it be true that does the duct from the ve-
liament,
a
nal,
First,-Where
scanty food is
and increases sicula umbilicalis in the kangaroo, and in cut down the herbivorous and carnivorous animals, termithe will Guardians mortality, nate in the intestinal canal ? dietaries with regret and slow deliberaSecond,—Where do the omphalo-mesention ; the consequences wi!l stare their con- teric artery and vein commence and terminate in both classes of animal ? sciences in the face. If they believe-and The vesicula umbilicalis, or vesicula the doctrine has been incessantly preached alba, or blastoderm, was known to Wm. in their ears-that when they lower the rates Hunter;he had even seen the duct filled with the same kind of fluid as the alimenand the dietaries they invigorate the sinews tary canal, but connected with it by an imof the pauper, the deterioration of the work- pervious thread. In the ninth edition of Burn’s " Mid. house diet may be expected to proceed in a wifery," p. 219, the blastoderm, or vesicula rapid progression. Liberal men, like Lord umbilicalis, is seen " entering the caudal RADNOR, when imbued with the fictitiousextremity by a short pedicle:’ In No. 597 of THE LANCET, p. 1029, Dr. belief that the " dyspepsia of the poor" is; states as follows :-" That on the " Grant simply caused by overfeeding," and that intestine of the newly-hatched and small the abstraction of butcher’s meat has " an even the mature bird, a minute coccal appeneffect altogether miraculous," in preventing dix is left in the situation where the yolkdisease, will rejoice to see the wages of the bag formerly opened into the alimentary labourer with a large family reduced to canal; this I have also seen on a correof the small intestine in the seven shillings a week, and they will regret sponding part human foetus." to see his condition ameliorated, when that " The duct terminating in the middle of amelioration places the insidious poison of the small intestines."—Burdoch. " Into the coecum."—Oken. « By a neck with the in. English beef within his reach. a
punishment,
59
testinal canal."—Bojenus. Breschet, Sallor, below, admits of a ready transmission of Woulf, and Beer, do not specify in what the fluid into it. Hence the whole intespart the duct terminates. Velpean states tinal canal is no more than an elongation of that he
canal,
pressed the fluid in the duct into the the dnct; specify where the dissected
but he does not
so
that if the intestinal canal be
out of the germ, it resembles the " The duct 1ermi. tendril of a vine, and is not like an open
duct itself terminated. nates at the lower part of the ileum."—
vessel, or gutter, as some authors have represented. There is great difficulty in disThe description of the termination of the tinguishing, during the first six weeks, what duct by Mr. Mayo, is the most remarkable is duct, or duodenum, jejunum, ileum, or of all. In his fourth edition, p. t2l, he cœcum, in the embryo. No person has yet thus writes: In a remarkable specimen given the measurement of the duct, and this belonging to Mr. Sweatman, the connection is a point which it is most important to of the vesicula alba with the alimentary know. In the human ovulum, and in the canal is beautifully shown. The vesicula cow, in both of which the same period of lies immediately without the amnios ; the gestation is occupied, the duct is always at whole length of the thread leading from it least six lines in length. This duct is first is an inch and a quarter; the length of the absorbed at its point of junction with the umbilical chord is 22-50ths of an inch; the vesicula umbilicalis. In the ovulum of the vessel is pear-shaped, 11-50ths of an inch cow the duct is pervious at thirty days, and in its long diameter, 8-50ths across. The at six weeks it disappears, all except the filament of the vessel joins the duodenum, remnant which is attached to the canal (inclose upon what seems the pylorus, or at testinal). This I prove by the date of copuMeckel.
about I.80th of an inch from it. It is sup- lation in this animal. posed that the embryo was about two months The length of the intestinal canal, as corai. old at the period of the sudden death of the pared with that of the body, is greater in mother." the foetrrs and in infants than in adults. It Now, Mr. Sweatman had seen a part of is generally longer, in proportion to the the series of my preparations, in which the body, in herbivorous than in carnivorous terminations of the omphalo-mesenteric ar- animals. The rule, however, has many extery and vein are shown. Subsequently, in ceptions; in the sloth, though herbivorous, a conversation with that gentleman, I re- the intestinal canal is scarcely as long as marked that I was amazed to hear him the body, while in the seal, which is carnideclare that the duct terminated in the duo- vorous, it is thirty times as long, The rat denum, and asked him if his specimen show- and mouse being omnivorous, have an intesed the omphalo-mesenteric artery and vein, tinal canal three times the length of their and where the vein terminated ; if the vessel bodies respectively; man seven times; the noted by him was the duct? To this he hog thirteen times. I believe that no anicould make no reply, but gave me the names mal but man and the ourang outang has of eight eminent authorities in London, who both a coecum and an appendix vermihad examined the specimen. I told him formis. that if the conclusions of these eight men M. Serres states that the lateral halves of were the same as his own, they were all in- the body are developed apart from each correct. He also stated that Mr. Owen had other, and afterwards coalesce. I must examined the specimen. I observed that differ from this authority, for I have dissecttrnth required no support from authority, ed the duct out of the human germ, and find but stood upon its own basis. He asked that there is no perceptible difference in me why I was so positive in my statement, thickness throughout its whole extent. I not having seen his specimen. I rejoined, have preparations showing the duct and the that the astronomer predicts the eclipse of omphalo-mesenteric artery and vein, all the sun long before its occurrence ; why, three dissected quite to the germ, but the then, should not the physiologist tell the parts are not fully developed, and might be formation of each organ as it proceeds to- disputed.* wards perfection ? Mr. Sweatman invited me to see the spe* From the preceding descriptions it is cimen, but not until it was put up in the bottle. I inquired why I was not among apparent that I cannot concur with M. the eight authorities who examined it, after Serres in the statement that the development I had studied embryology as I have done, of the embryotic animal is from the surface for so many years, and he visiting me very of its two lateral halves, towards the mesial often, and seeing my preparations. Alas ! line. The instance adduced will show that I am a poor mechanic, the law which he wishes to- establish is not of universal application. At a future Termination of the Duct, proceeding from the probably in my forthcoming publicaVesicrclce Umbilicalis, in the Germ, tion, I shall advert to the formation of the The duct from the vesicula umbilicalis uterus and the bladder, as affording further shoots into the germ, which, being always evidence against M.Serres’ views. -
period,
60
yolk- the ileum in the mammalia, which fact was in general, is in the coecum. observed by Meckel, who is the only phy. In most birds there is no caecal valve, and siologist, out of thirteen authorities whom I in many there is no coecum, consequently have named, that nearly approaches the the duct must terminate in another part of truth. The remnant of the duct in the kan. the canal, as is the case with those ovivipa- garoo, in my series of preparations, is in the InI middle of the appendix vermiformis, analo. rous animals which have no coecum. sharks I have found the duct gous with what is shown in the engraving0 of above, but close to, the valve. The duct the cat. terminates sometimes at the lower part The termination of the duct of the
bag
in
birds,
of
terminate
Human OCMM a.
atfii-st Week.
Flocculent chorion.
b. Chorion membrane. !;.
Amnion membrane.
d. Stomach. e.
Duodenum.
f. Vesicula umbilicalis.
g.
Separation of the
oiriphalo-mesenteric
vein and artery. le. vein accidentally in the dissection. ruptured
Omphalo-mesenteric
i. Omphalo-mesenteric artery. k. Urachus communicating with
bladder. 1. The umbilical chord.
the
61
Duodenum. f. Appendix vermiformia. g. Remainder of the duct from the vffuumbilicalis.
Fœtus of the Cat at the sixth Week. a. Alantois. b. Urachns bladder.
e.
i thecula ,
communicating with
d. Stomach.
h.
’i
i.
Omphalo-mesenteric vein. Omphalo-mesenteric artery.
in the germ, and that the vesicula umbili. calis receives them ; this is incorrect. The omphalo-mesenteric artery and vein are formed upon the surface of the vesicula, shoot alongside of the duct, into the the artery terminating in the anterior small branches of the mesentery of the their origin or their termination. In BresIn the whole course of my dissecchet’s work the same omission is observ- tions I have only once found the artery terable ; hence I imagine, that if these au- minating posteriorly, and that was in a thors had preparations, showing the fact, human embryo. The mesenteric arteries of them would have appeared in proceed towards the vena portaR ; the vein engravings their works. Pockels states that the om- enters another vein of the duodenum, near
Termination of the
O)nphalo-Illesenteric Artery and Vein. Wrisberg, in 1764, gives the best drawing of this, but says that the bifurcation is pretended. In Velpeau’s work there are eight plates of the vessels, but none of them show
phalo-mesenteric artery and vein are formed
and germ, ileum.
the
pylorus; the veins of the intestines run
62
the small quantity of the vitellus the ovum in the ovary contains, dis. which portæ.* the first few days, and is appears The first Circulation in the Embryo. consumed in the rapid formation of the vesi. The blood is first seen on the surface of cula umbilicalis membrane. the vesicula umbilicalis, or blastoderm. Second; The fluid contained in the vesiThe blood-vessels proceed from its surface cula umbilicalis is a secretion, and not a with the duct, into the germ. If analogy nutrient fluid, because the quantity in. derived from the cow can be admitted in creases rather than diminishes during the reasoning on the human species, blood- early development of the embryo. vessels are seen on the 18th day; and the Third,-As the embryo becomes developheart is not formed complete until the 30th ed a small portion of the blastoderm memday, so that the circulation is performed as brane is found attached to the intestine by in some of the lower animals which have no a very small pedicle, of which the greater hearts. The views of Professor Alison, re- portion is on the outside of the belly. garding the self-moving power in the blood, Fourth,—In the rabbit this vessel is very are beautifully borne out by the first circu- considerable, and the embryo, whose abdolation of the germ, if it be admitted that men is turned towards it, is sunk in a desuch a power exists at all in the blood. I pressed line in the vessel, and this becomes, believe this to be the first time that the by degrees, inclosed in a double bag, simiorigin and termination of those vessels has lar to that which is formed by a double been explained. nightcap on the head. This development of In M. Coste’s " Memoir," 1834, the fol- the embryo is only in the rodentia. Fifth,-That the embryo of the other mamlowing statements are found:— First; That the ovum of the rabbit is malia has a different origin. completely free from adherence to the uterus Sixth,—On the ninth day we also begin for the first nine or ten days ; that the nutri- to see the omphalo-mesenteric vessels passtion which the embryo receives is derived ing from each side of the embryo to the from the fluids secreted by the uterus, be- inner surface of the invaginated vessel._________________________________ (LANCET, No. 628). * These vessels go to form the first porWhile reviewing those statements from tion of the vascular system of the foetus, M. Coste’s "Memoir," I beg attention to the which is the vena portae, which terminates following observations :in the liver. This will serve to explain the First,-That the vesicula umbilicalis is great size of that viscus before the heart is formed in the ovary, and not in the uterus; formed; and it is well known that the um- and that the vitellus which it contains does bilical vein from the placenta, in the second not form the membrane. circulation, terminates in that organ also. Second,—That the embryo derives its The great size of the liver in the foetus has whole nutrition from the vesicula umbilicaattracted the notice of physiologists in all lis. The vesicula is four or five times larger ages, and various conjectures have been than the germ, when first visible, and the offered to explain that phenomenon. Dr. vitellus diminishes as the development of Robert Lee, in the " Philosophical Trans- the germ proceeds. actions"for 1829, attempts to show that the Third,—M. Coste does not specify in liver is an organ which secretes albumen what portion of the intestinal canal the duct during foetal existence, and forms albumen terminates. This point will be found clearfor the nourishment of the foetus. The ed up in a former part of this paper. Doctor’s ideas must be imaginative, and not Fourth,—That the vesicula umbilicalis in deduced from facts; as he thus maintains the rabbit is three lines in length, and one that the organ performs two functions, and a half in breadth. Instead of the vesinaraely, that of secreting albumen before, cula umbilicalis being larger in the rabbit and bile immediately after, the birth of the it is smaller. child. The difference between albumen and Fifth,—There is no difference in the g;erbile is as great as between any two secre- minal origin of the rabbit and the other tions of the body. I have dissected 135 mammalia. Sixth,—M. Coste does not point out either embryos and foetuses, and have never found albumen in the gall-bladder, but a consider- the commencement or the termination of the able quantity of gall is universally found omphalo-mesenteric artery and vein, the in the cystic bag during the whole period of description of which I have likewise forfoetal existence. If the liver be an organ merly given. Would it be believed that a man who had which secretes albumen for the nourishment of the foetus, I would ask Dr’. Lee to ex- been studying embryology during eight plain the source of nutrition in those cases years could, on the presentation of such a in which the liver is wanting. There are Memoir, obtain from the Institute of France many such on record ; that of Dr. Clarke, a gold medal ? Where are the preparations " Phil. Trans." 1793 ; and that of Sir B. that accompanied, or ought to accompanied the Memoir? . Is ihere-none to illusBrodie, 11 Phi!. Trans." 1809, are
into the
meseraic, which
go to the
vena
cause
instances,
have
63
trate the points advanced? or has the author not know in what species of rats Mr. Owen no other support for his views than the ima- found this large vesicula umbilicalis ; but I ginary ideas of a man who never studied the have preparations of the sow showing the book of nature ? If lie really possess proofs vesicula eight times larger than the vesicula I fear that he has only mutilated what he in rats which I have dissected; and he like. had seen, for he never could have commit- wise states that the vessel is more perenanent in rats than in other animals. The preted such errors to paper. That the embryo of a rabbit sinks into the parations of the human placenta in my vesicula umbilicalis, and forms a double series show the vesicula with the omphalobag, similar to a nightcap, is an anomaly mesenteric artery and vein at the ninth The truth is, month ; which is denied by Velpeau and all never to be found in nature. that M. Coste never has seen the vesicula authorities; and I could convince Mr. Owen umbilicalis in the rabbit, for the vesicula is that it is more permanent in the human subonly three lines in length, and one and a ject than in animals. What resemblance the half in breadth. No doubt the vesicula in ovum of rats bears to that of kangaroos, and the kangaroo was a wonder to him, for he the ovum of kangaroos to that of birds, it is has never seen it in any other animal, not not for me to say. I will leave Mr. Owen to even in a rabbit, but represents the alantois illustrate that point; but if any analogy obfor that vessel. tains, the viviparous should be compared The preparation above described was ex- with the oviviparous, and not with the ovihibited on August the 22nd, 1837, at the parous, which all authors on embryology have done. It is now many years since I Zoological Society. Mr. Owen’s paper read before the Royal demonstrated by preparations that the emSociety in London, in 1834, has also attracted bryo of all animals is nourished by a vesiduring the last three years a considerable cula umbilicalis, or yolk-bag, such as the share of attention in Britain, as well as on oviviparous, and not by an alantois, as has the Continent, amongst physiologists,—the been represented by M. Coste and Mr. exhibition of a foetus o-f a kangaroo and its Owen,-the one to the Royal Institute of membranes, at the middle period of gesta- France, the other to the Royal Society of tion, which in that animal lasts 38 or 39 London, the papers respectively being read days, being a novelty in comparative ana- in 1834. That these gentlemen are not tomy. The appearances described were themselves very well satisfied with their found on about the 20th day after impreg- vaunted discoveries, I collect from the fact, nation, when, he states, ‘there was no pla- that they have both lately, in 1837, ancental structure, nor villi, nor the appear- nounced to the Academy of Science in Paris ance of vessels in the uterus nor the chorion." the discovery of another vesicula umbilicaNow, if the reader will examine the uterus lis in the kangaroo ; and M. Coste makes of a mare, or a sow, he will find precisely mention of the name of Mr. Owen in the disthe same appearance at the same date after covery, but Mr. Owen never adverts to that copulation, up to the fifth week, in both ani- of M. Coste. I have little doubt that before mals, and the same appearance on the foetal 1839 they will discover another, as all the membranes. It is during this period in world knows that they are both men of those animals which go longer than five "great scientific research," and physiology months in utero-gestation, that the embryo is greatly indebted to them for their discois supported or nourished by the omphalo- veries. JonN MILLER, JOHN MiLLER, Mechanic. mesenteric vessels, from the vesicula umbi1838. March, 1838. licalis, and not from the vascular membrane 3, Theobald’s-road, March, or sac, which is the alantois. Hence I doubt whether Mr. Owen ever saw the vesicula VIBRATORY CYLINDERS RECENTLY umbilicalis, or he never would have so inDESCRIBED BY HENLE* correctly represented for it, tlae cclarrtois; and HENLE scraped a little mucus frorn the it is somewhat singular that Mr. plaeed it under the should perpetuate the same error as I have bodies, nearlv cylindrical in of M. the conduct previously exposed of the form of incisor of considerable
3, Theobald’s-road,
Owen larynx ofa frog, and
rnicooscope, when
Coste.
size,
were
teeth, seen revolvingslowly.while small
London’s "Mag. of Nat. Hist.," 1837, it. vesicula umbilicalis, butthathe did11 thenot know vesicula He likewise of theofcylm. extremity in a fringe cilia, apparent along the;larger it laypresents fine umbilicalis is largest in the glires, came der. long body, cylinder exhiThe which is next to themarsupiata, and nucleus, and surmounted by bits a striking affinityto birds,&c." I do containing in the stomach and intestines cilia cilia ;
in moved about in every direction; In Owen describes the two sacs, and the globules Mr. a few minutes all became still. But before pyriform sac he calls the alantois. It is the motion ceased, the cause of the motion be-
declares
order
a
a
but
the mouth the long cylinare wanting; is flattened into a polyedric body in
’ M. Coste saw the vesicula in the kandrical garoo with Mr. Owen, in London, 1837. No. 742. See LANCET,
!
* In
an
Inaugural Thesis.