12 GENERAL PRINCIPLES OF ZOOLOGY. 



larly valuable in the description of new species, inasmuch 

 as it from the very beginning informed the reader to what 

 position of relationship the new species was to be assigned. 



In his characterization of the various systematic groups 

 Linnaeus broke completely with the hitherto-prevailing 

 custom. His predecessors, as Gessner, Aldrovandus, in 

 their Natural Histories had given of each animal a ver- 

 bose and detailed description, from which the beginner 

 was scarcely able to deduce what was specially charac- 

 teristic for that animal, a matter which should have been 

 chiefly emphasized in the definition. Linnaeus, on the 

 other hand, introduced brief diagnoses, which in a few 

 words, never in sentence form, gave only what was neces- 

 sary for recognition. Thus a way was found by which 

 it would be possible to insure comprehensibility in the 

 enormously increasing number of known animals. 



Influence of the Linnean System. But in the great 

 superiority of the Linnean System lay at the same time the 

 germ of the one-sided development which Zoology came 

 to take under the influence of Linnaeus. The logical 



o 



perfecting of the System, which undoubtedly had become 

 necessary, gave that a brilliant aspect, and hid the fact 

 that systemization is not the ultimate purpose of investi- 

 gation, but only an important and indispensable aid to it. 

 In the zeal for naming and classifying animals, the higher 

 goal of investigation, knowledge of the nature of animals, 

 was lost sight of, and the interest in Anatomy, Physiology, 

 and Embryology lagged. 



From these reproaches we can scarcely spare Linnaeus 

 himself, the father of this tendency. For while he in his 

 " Systema Naturae" treated of an extraordinarily larger 

 number of animals than any earlier zoologist, he brought 

 about no deepening of our knowledge. The manner in 

 which he divided the animal kingdom, in comparison with 

 the Aristotelian system, is to be called rather a retro- 

 gression than an advance. Linnaeus divided the animal 

 kingdom into six classes: Mammalia, Aves, Amphibia, 

 Pisces, Insecta, Vermes. The first four classes correspond 



