SYSTEMATIC ZOOLOGY 263 



clear our central purpose and formulate some of the principles that 

 guide us in our work. In attempting to do this, I am obviously speak- 

 ing only for myself. I could not, even if I would, express another 

 worker's motives or principles. The excuse for publishing my own is 

 two-fold ; the thought that they may be in some way suggestive to other 

 systematists, and the larger hope that they may serve to increase the 

 mutual sympathy between all classes of zoologists. 



There seem to be at least three current opinions as to systematic 

 zoology. One is that it is engaged in the vast undertaking of cataloguing 

 the animal kingdom. Every species of animal must be listed and hence 

 must have a name, or, at least, a number. That the names may be 

 attached to the right animals, descriptions and figures must be pub- 

 lished. As there are still an unknown number of unnamed species, the 

 describing of new species is the most important part of systematic 

 work. The remainder consists of arranging in some sort of compre- 

 hensible system the thousands of names already in use. This type of 

 systematic work is well shown in Linne's " Systema Naturas," the pur- 

 pose of which is, frankly, to give a complete catalogue of all natural 

 objects. The confidence that such a catalogue would be immensely 

 useful for many purposes was a sufficient incentive to undertake the 

 labor involved. 



A second opinion of systematic zoology, which has found expression 

 several times since the opening of the twentieth century, is at the other 

 extreme from the preceding. This very modern view is that systematic 

 zoology covers the whole field — morphology, physiology, embryology, 

 histology, paleozoology, even cytology are but assistants in systematic 

 work. As taxonomic characters occur obviously on the exterior, so they 

 occur no less really, though obscurely, in the internal structure, in the 

 performance of functions, in the tissues, in the development, even in 

 the mitotic figures in the cells. As comparative study of recent animals 

 is essential to a proper understanding of character values, so the careful 

 study of fossils and the revelations of the geological record are supremely 

 important for systematic work. According to this view, the systematist 

 is not the assistant erecting the scaffolding with the aid of which the 

 real building is to be done by the other specialists, but he is himself the 

 master-builder and the others are the carriers of material with which 

 he may build. 



The third opinion of systematic work, held in some degree by many 

 zoologists, though often more or less unconsciously and seldom openly 

 avowed, is that it forms an elementary sort of study which has a certain 

 educational value in training the eye and the judgment of those who 

 are to become zoologists. It bears much the same relation to zoology 

 proper that arithmetic does to what we call higher mathematics, and 

 the really able man will not delay in it, after he has secured the training 



