138 cook: determining types of genera 



marily to the definitions of the natural groups, but as attached 

 to the groups themselves, through the medium of types. Each 

 species has its type specimen, each genus its type species. 



The method of naming the concepts was used by Linnaeus 

 and his followers for over a century, but had to be abandoned 

 on account of the confusion caused by names slipping away from 

 their original application. Types not being recognized, the ap- 

 plications of the names varied with interpretations of the defini- 

 tions. Two or more names often became current for the same 

 genus, or the same name for two or more genera. How to place 

 the older names on a type basis is still a problem. 



Priority governs the acceptance of names and should also 

 determine the application of names. Priority of application 

 means that a name should remain with its original type. Cer- 

 tainly no practical purpose is served by accepting a name unless 

 the application is determined. Names without applications are 

 worse than useless. 



Generic names that have been misapplied need to be re- 

 stored to their original applications and fixed by the recognition 

 of types. But by using wrong methods in the work of restora- 

 tion it is possible to damage the taxonomic structure still more. 

 Historical continuity is sacrificed when names are carried away 

 from their original applications. This objection lies against all 

 of the arbitrary methods of fixing types, whether we take as 

 types the last species by elimination, the first species named, or 

 the first species to be designated as type by a later author. The 

 method of elimination is most defective, because it does not give 

 the same results in the hands of different students and because 

 it often leads away from the true type. Obscure names are 

 brought out for prominent genera, and prominent names trans- 

 ferred to obscure species. The confusion is worse than if the 

 transferred names had been discarded altogether. 



The need of more care in determining the original applications 

 of names may be illustrated by an example from millipeds. 

 The generic name Spirobolus has been used for a very large group 

 of tropical species with their chief center in South America. 

 The genus was established by Brandt in 1833, with two species 



