On the (Jlassification of Animals. 269 



improve somewhat our present mode of drawing up defini- 

 tions, if not of classifying. Those acquainted with such 

 works as Gunther's "Classification of Fishes" must know 

 that the various groups are usually considered as if they in- 

 cluded independent and specially created forms, and no attempt 

 other than grouping allied forms together is made, either to 

 indicate their relationship or the amount of elaboration or 

 specialisation that has taken place. Further it must have 

 been observed that Haeckel and others have long recog- 

 nised the necessity of a change in our mode of classifying 

 and defining organisms, and especially of adopting a simpler 

 and more philosophical plan than has hitherto been followed, 

 so that in venturing to indicate on what lines our classifica- 

 tions might in future be conducted, I am only following the 

 example of other naturalists. 



The system which I would recommend will be best illus- 

 trated by taking a familiar group as an example. I know of 

 no group that will serve better for this than the fish gToup. In 

 the Fishes I would, at the outset, draw up a short definition 

 containing only absolute characters, and, as far as possible, 

 characters which would not only suggest, but in a great 

 degree be applicable to the ancestral forms. This short 

 statement made, each order would next be dealt with sepa- 

 rately. Before giving any definitions I would enumerate all 

 the genera of the order, showing in as graphic a manner as is 

 possible how, on a flat surface, these might be arranged into 

 sub-families, families, and suborders or other groups. This 

 done, I would next draw up a short definition of the order, 

 containing, as in the definition of the class, only absolute 

 characters. If two or more suborders, I would select the one 

 which seemed to approach nearest to the ancestral forms and 

 draw up an exhaustive statement of its characters ; in other 

 words, I would describe in a categorical fashion a typical 

 member of the group. 



Having done this I would next indicate as shortly as 

 possible how the members of this particular family differed 

 from the type described, either by being more elaborated or 

 specialised, or by having undergone degradation. When 

 necessary, in addition to showing the relation of each genus 



