Age determination in the venomous snake Habu,

Hwxwsfn, Y. and Twtvwrw, H. Age determination in the venomous snake Habu, Trimeresusua flavoviridis . lap. l. exp. Med 51, 209 (1981) . FOR DSfEAlIIIdING the age of Habu (TÜmertsurua Jiavoviridia) from the Amami Islands of Japan, the frequency distribution of body length, principal components analysis and the number of annual layers were investigated . The eggs of Habu are laid only in July and hatch after about 40 days . Therefore, most snakes are regarded as starting to develop in August . Since the 123 snakes ~:a*n ;n in this study were killed in June, they could be divided into age groups with intervals of 12 months . The ages of snakes were estimated to be 12n+10 months, where n is the age is years. The frequency distribution of body length showed 4 peaks; the 1st peak (mean: 527 mm) was determined as age group 10 months, the second peak (mean: 802mm) corresponded to age group 22 months, the third (mean: 1049 mm) to 34 months and the fourth (1252 mm) to 46 months . Age groups older than 46 months could not be well analysed because there were fewsperimens of larger snakes. Though there was separation into four age groups based on the first principal component, the discriminatory power was not so strong. The number of annual layers was examined in the ectoptergoid bone of the skull. In spite of thepresence of accessory bands, the principal bands could be recognized for up to 7 annual layers . However, the age of 18 snakes could not be determined because of the difficulty in d;atin ~;sh;n g old layers . Y. Swwwr PnvxEx, R. The Snake Book. New York : Doubleday &, Co ., Inc. (1981) . Trass rs an interesting, well put-together, and very informative little book on snakes, their habitats, care and feeding, collecting, venomous and nonvenomous species, general behaviour, the treatment of snake bite and a varied number of associated topics, including an interesting one on the opportunities in herpetology . The book is writtenin an easy-reading style and has anumber of black and white photographs, line drawings and a sufficient number of tables to give the reader a good knowledge of snakes . It ie not intended to be a definitive text for the herpetologist but should provide interesting reading for the layman . The price is reasonable at 513.00. F. E. RUSSELL LUGNirER, A.-A.J. and RErEtEa, B. Mechanism of ricin action on a wheat gene cell-free protein synthesizing system . Pl. Sci. I_eu. 23, 71-80 (1981) . Pao~tw synthesizing systems derived from crude extracts, as well as from partially purified 70S ribosomes, and elongation factors from Esch~richiacoli were treated with ricin, ricinA and B chains or ricin tryptic hydrolysate. times more resistant to ricin than those from rabbit reticulocytes . However, the mechanism of ricin action is wmparable in the two systems. In both of them, a period of active protein synthesis is required before inhibition occurs and the activation of the ricin molecule coincides with ricin subunit formation. G. HwaEa~tErrL Haves-Korflv, J.G ., Lucxma, A.-A.J ., T®orn, O., tûrEatu, O. and DntiIEIMER G. Inhibition of Eaciurichia coli protein synthesis by a limited tryptic digest of ricin, the toxin of Ricinrcr communia L. seeds. Biochem. biophya. Res. Commun . 97, 962-967 (1980) . PR01F.I N synthesizing systems derived from crude extracts, as well as from partially purified 70S ribosomes, and elongation factors from Eaclurichiacoli were treated with ricin, ricin A and B chains or ricin tryptic hydrolysate. Ricin and its isolated chains do not inhibit protein sytheais in these systems. However, a tryptic hydrolysate of ricin inhibits both Etcleerichia coli protein synthesizing systems. These results demonstrate that, although ricin and its two polypeptides A and B have no activity on Eacherichia coli protein synthesis, some tryptic products) of ricin are able to inhibit protein synthesis in procaryotes. Thus, it appears that fragments smaller than ricin or its two polypeptides can inactivate 70S~ribosomes. G. HwaFQ~r?w L

Caarrx, E.D ., Luctvrna, A.-A.J ., BF.C%, G ., DmrrEten3tc, G., PErzrxcErt, E. and FwererErc, M. Comparative studies by scanning electron microscopy of the effect of ricin on the cell membrane of hepatoma cells and isolated hepatocytes. 7bsic. Europ. Res. 3, 180-184 (1981) .