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In defence of the “Indented” layout for keys
31
IN DEFENCE OF THE "INDENTED" LAYOUT FOR KEYS R.W. Rayner
Parker-Rhodes' article "The Art of Keys" (this Bulletin 8.2,p.68) is a most interesting and detailed account of the structure and typography of keys for the identification of taxa as well as of the techniques that may be used in composing them. Many of the recommendations are valuable and I find myself, with a few exceptions, in broad agreement with the various points made. However there is an important one over which I feel I must join issue with him and that is his summary condemnation of the "offset" or "indented" layout, which I find quite unjustifiable. It seems to me that both this layout and the alternative "numbered", or as I prefer to call it, "bracketed" type, have their advantages and disadvantages and that these are fairly evenly balanced. It may not be easy to decide which type is preferable and the choice between them may to some extent be a matter of taste. My own preference is strongly for the "indented" layout and consequently I should like to enlarge on its merits and encourage anyone contemplating publishing a key to give due consideration to the advantages that this type presents. To me one of the more important of the advantages is that the structure is much more easily appreciated visually than with the bracket type. Both have, of course, the same basic hierarchical (tree-like) form, but whereas the order of branching is immediately apparent in the indented key, the branches appearing in logical sequence from left to right across the page, those of the bracket type are interwoven into what is at first sight an orderless tangle, only to be resolved by following an intricate series of number clues. What position any final branchlet giving the name of a taxon, and hence the taxon itself, occupies in the hierarchy is quite impossible to appreciate without many passages back and forth through the maze of branches. In the indented type it is a simple matter to appreciate the position of each taxon in relation to the others and to observe how many share the same characteristics. In this way a mental picture of the grouping of the taxa keyed out may be relatively easily and rapidly obtained, a feat which may often take much time and patience and is not infrequently nigh impossible if only a bracket key is available. Of course if the key is only to be employed for a more or less mechanical identification of taxa, this consideration would not be of importance, but surely the most serious students would normally prefer to gain a better understanding of the group to which the taxon they are identifying belongs at the same time as obtaining its name? To me this is the most valuable asset possessed by this type of key and one which has, on occasion, led me to recast a bracketed key in indented form. This advantage is very important where a key is primarily used to exhibit taxonomic relations (i.e. is a "systematic" one), and is the more usual form in which such keys are presented. However even with socalled "artificial" keys the knowledge of the distribution of the characters used amongst the taxa within a group that it is possible to gain with relative ease from the indented layout, can be most helpful. It is especially valuable for the subsequent identification of these taxa and their separation from related taxa at sight. To a very limited extent it is possible to introduce something of this nature into bracket keys by the device of "cross-headings" as described by Parker-Rhodes, though this does use up more space and thus reduces one of the principal advantages of the bracket layout. The third important advantage of indenting is that it eases the retracing of one's route through the key should it be suspected that erroneous choices or
32 judgements may have been made. This presents no problems and may be rapidly carried out with this layout, whereas with bracket keys such a process is very difficult , if, as usual, back references are not given. Even if they are it is still cumbersome, slow and tedious. The ease with which one can retrace one's path in the indented key also makes it possible to read back the whole series of diagnostic characters appertaining to a given taxon and used in the key. This may be useful in itself and not only for checking an identification. What then are the disadvantages of indented keys? According to ParkerRhodes they are "wasteful of space, difficult to read and ugly". I have little idea what he means by their being "ugly" and in any event such a judgement is subjective only. Personally I find indented keys visually more attractive than bracketed ones, but obviously I must have different ideas of what constitutes ugliness in keys! Further discussion of the aesthetics of key layouts is unlikely to be rewarding since personal taste is the deciding factor. That indented keys take up rather more space is true, though the difference is reduced if cross-headings and back references are incorporated into the bracket type. The space occupied may also be reduced considerably if the distance insetting is kept to a minimum by using a system of numbering or lettering to identify and locate the alternatives at each branch point. Where the key is a long one, splitting it into sections in a preliminary key (as in my own Russula) or the remainder ("reste ") system used by Kuhner and Romagnesi in the "Flore Analytique" avoids the Alice-in-Wonderland dormouse's tail effect found in some of Singer's keys and in those in Hubbard's paper-back on grasses. By "difficult to read" I presume is meant that the alternatives at a branch point are often not adjacent to each other, but may be separated by a considerable vertical distance, and sometimes indeed, are not on the same page. This entails shifting the level of vision down the page or turning the page. In practice locating the alternative is usually no appreciable hindrance provided it is clearly identifiable by a number or letter. If it is on the next page this may easily be indicated at the bottom of the preceding one. A greater separation is best avoided by dividing the key into sections as described above. To my mind this disadvantage, together with that of the greater space requirement, is a small price to pay for the big advantages described earlier. I hope this short note will do something to redress the balance in favour of the indented layout and will persuade intending constructors of keys to give serious and thoughtful consideration to its merits.
FUNGI ON STAMPS Bruce Ing The exhibits arranged by Dr Hilda Canter-Lund and Mr C.J. La Touche at the Society's FUNGI '73 Exhibition created a good deal of interest and the Editor of the Bulletin readily agreed to publish a short catalogue of stamps depicting fungi. Altogether 93 stamps have been issued to date , from 20 countries. The first of these was the unusual Japanese issue of 1948, but the first to show a fungal portrait was the set from Rumania in 1958. 55 species are represented and it is not surprising to note that, with several central African, east Asian and eastern European states involved, 37 of these are eaten with considerable relish. Examples are the parasol, St. George's, Chinese white and field mushrooms, shii-take, chanterelle, morel, boletes and the termite fungi. Several poisonous species are included of which Death Cap and Fly Agaric need no comment. In contrast a yeast, Penicillium and a stinkhorn also appear in the list.
IN DEFENCE OF THE "INDENTED" LAYOUT FOR KEYS R.W. Rayner
Parker-Rhodes' article "The Art of Keys" (this Bulletin 8.2,p.68) is a most interesting and detailed account of the structure and typography of keys for the identification of taxa as well as of the techniques that may be used in composing them. Many of the recommendations are valuable and I find myself, with a few exceptions, in broad agreement with the various points made. However there is an important one over which I feel I must join issue with him and that is his summary condemnation of the "offset" or "indented" layout, which I find quite unjustifiable. It seems to me that both this layout and the alternative "numbered", or as I prefer to call it, "bracketed" type, have their advantages and disadvantages and that these are fairly evenly balanced. It may not be easy to decide which type is preferable and the choice between them may to some extent be a matter of taste. My own preference is strongly for the "indented" layout and consequently I should like to enlarge on its merits and encourage anyone contemplating publishing a key to give due consideration to the advantages that this type presents. To me one of the more important of the advantages is that the structure is much more easily appreciated visually than with the bracket type. Both have, of course, the same basic hierarchical (tree-like) form, but whereas the order of branching is immediately apparent in the indented key, the branches appearing in logical sequence from left to right across the page, those of the bracket type are interwoven into what is at first sight an orderless tangle, only to be resolved by following an intricate series of number clues. What position any final branchlet giving the name of a taxon, and hence the taxon itself, occupies in the hierarchy is quite impossible to appreciate without many passages back and forth through the maze of branches. In the indented type it is a simple matter to appreciate the position of each taxon in relation to the others and to observe how many share the same characteristics. In this way a mental picture of the grouping of the taxa keyed out may be relatively easily and rapidly obtained, a feat which may often take much time and patience and is not infrequently nigh impossible if only a bracket key is available. Of course if the key is only to be employed for a more or less mechanical identification of taxa, this consideration would not be of importance, but surely the most serious students would normally prefer to gain a better understanding of the group to which the taxon they are identifying belongs at the same time as obtaining its name? To me this is the most valuable asset possessed by this type of key and one which has, on occasion, led me to recast a bracketed key in indented form. This advantage is very important where a key is primarily used to exhibit taxonomic relations (i.e. is a "systematic" one), and is the more usual form in which such keys are presented. However even with socalled "artificial" keys the knowledge of the distribution of the characters used amongst the taxa within a group that it is possible to gain with relative ease from the indented layout, can be most helpful. It is especially valuable for the subsequent identification of these taxa and their separation from related taxa at sight. To a very limited extent it is possible to introduce something of this nature into bracket keys by the device of "cross-headings" as described by Parker-Rhodes, though this does use up more space and thus reduces one of the principal advantages of the bracket layout. The third important advantage of indenting is that it eases the retracing of one's route through the key should it be suspected that erroneous choices or
32 judgements may have been made. This presents no problems and may be rapidly carried out with this layout, whereas with bracket keys such a process is very difficult , if, as usual, back references are not given. Even if they are it is still cumbersome, slow and tedious. The ease with which one can retrace one's path in the indented key also makes it possible to read back the whole series of diagnostic characters appertaining to a given taxon and used in the key. This may be useful in itself and not only for checking an identification. What then are the disadvantages of indented keys? According to ParkerRhodes they are "wasteful of space, difficult to read and ugly". I have little idea what he means by their being "ugly" and in any event such a judgement is subjective only. Personally I find indented keys visually more attractive than bracketed ones, but obviously I must have different ideas of what constitutes ugliness in keys! Further discussion of the aesthetics of key layouts is unlikely to be rewarding since personal taste is the deciding factor. That indented keys take up rather more space is true, though the difference is reduced if cross-headings and back references are incorporated into the bracket type. The space occupied may also be reduced considerably if the distance insetting is kept to a minimum by using a system of numbering or lettering to identify and locate the alternatives at each branch point. Where the key is a long one, splitting it into sections in a preliminary key (as in my own Russula) or the remainder ("reste ") system used by Kuhner and Romagnesi in the "Flore Analytique" avoids the Alice-in-Wonderland dormouse's tail effect found in some of Singer's keys and in those in Hubbard's paper-back on grasses. By "difficult to read" I presume is meant that the alternatives at a branch point are often not adjacent to each other, but may be separated by a considerable vertical distance, and sometimes indeed, are not on the same page. This entails shifting the level of vision down the page or turning the page. In practice locating the alternative is usually no appreciable hindrance provided it is clearly identifiable by a number or letter. If it is on the next page this may easily be indicated at the bottom of the preceding one. A greater separation is best avoided by dividing the key into sections as described above. To my mind this disadvantage, together with that of the greater space requirement, is a small price to pay for the big advantages described earlier. I hope this short note will do something to redress the balance in favour of the indented layout and will persuade intending constructors of keys to give serious and thoughtful consideration to its merits.
FUNGI ON STAMPS Bruce Ing The exhibits arranged by Dr Hilda Canter-Lund and Mr C.J. La Touche at the Society's FUNGI '73 Exhibition created a good deal of interest and the Editor of the Bulletin readily agreed to publish a short catalogue of stamps depicting fungi. Altogether 93 stamps have been issued to date , from 20 countries. The first of these was the unusual Japanese issue of 1948, but the first to show a fungal portrait was the set from Rumania in 1958. 55 species are represented and it is not surprising to note that, with several central African, east Asian and eastern European states involved, 37 of these are eaten with considerable relish. Examples are the parasol, St. George's, Chinese white and field mushrooms, shii-take, chanterelle, morel, boletes and the termite fungi. Several poisonous species are included of which Death Cap and Fly Agaric need no comment. In contrast a yeast, Penicillium and a stinkhorn also appear in the list.