LEADING GROUPS OF EXISTING SYSTEMS 195 



almost ceased to engage the attention of the more careful original in- 

 vestigators, will be revived, and the manifold ties which link together 

 all animals and plants as the living expression of a gigantic concep- 

 tion, carried out in the course of time, like a soul-breathing epos, 

 will be scrutinized anew, determined with greater precision, and ex- 

 pressed with increasing clearness and propriety. Fanciful and artificial 

 classifications will gradually lose their hold upon a better informed 

 community; scientific men themselves will be restrained from bring- 

 ing forward immature and premature investigations; no characteris- 

 tics of new species will have a claim upon the notice of the learned 

 which has not been fully investigated and compared with those most 

 closely allied to it; no genus will be admitted, the structural peculi- 

 arities of which are not clearly and distinctly illustrated; no family 

 will be considered as well founded which shall not exhibit a distinct 

 system of forms intimately combined and determined by structural 

 relations; no order wdll appear admissible which shall not represent 

 a well-marked degree of structural complication; no class will de- 

 serve that name which shall not appear as a distinct and independent 

 expression of some general plan of structure, carried out in a peculiar 

 way and with peculiar means; no type will be recognized as one of 

 the fundamental groups of the animal kingdom which shall not ex- 

 hibit a plan of its own, not convertible into another. No naturalist 

 will be justified in introducing any one of these groups into our 

 systems without showing: 1st, that it is a natural group; 2d, that it 

 is a group of this or that kind, to avoid, henceforth, calling groups 

 that may be genera, families; groups that may be orders, fam- 

 ilies; groups that may be orders or classes, classes or branches, respec- 

 tively; 3d, that the characters by which these groups may be recog- 

 nized are in fact respectively specific, generic, family, ordinal, classic, 

 or typical characters, so that our works shall no longer exhibit the 

 annoying confusion which is to be met almost everywhere, of generic 

 characters in the diagnoses of species, or of family and ordinal char- 

 acters in the characteristics of classes and branches.^^ 



It may perhaps be said that all this will not render the study of 



^^ As I do not wish to be personal, I will refrain from quoting examples to justify 

 this assertion. I would only request those who care to be accurate to examine critically 

 almost any description of species, any characterization of genera, of families, of orders, 

 of classes, and of types, to satisfy themselves that characters of the same kind are in- 

 troduced almost indiscriminately to distinguish all these groups. 



