6 GENERAL PRINCirLES OF ZOOLOGY 



This neglect of the systematic side is further shown in (he fact (hal (he 

 great phikisopher is satislied \\-il]i two syslematic categories, with tlSa, 

 species or kind, and yeVos or group. His eight yo'?; juc'yicrra Avoukl ahout 

 correspond with the Classes of modern zoology; they have been the start- 

 ing-point for all later attempts at classification, and may therefore be 

 enumerated here: i. Mammals (^ojoTOKovrra ti'av'roTs). 2. Birds (opn^cs). 

 3. Oviparous quadrupeds {TeTpdwoSa uioTOKovvra) . 4. Fishes {IxOvti). 

 5. ^Molluscs (fjLaXixKia). 6. Crustaceans [jxaXaKo'aTpaKa). 7. Insects 

 (li'To/ia). 8. Animals with shells (oo-TpaKoSt/u/iara). Aristotle also noticed 

 the close connection of the first four groups, since he, without actually 

 carrying out the division, contrasted the animals with blood, ivaipa (belter, 

 red blood), with the l)loodless, diuL/xa (better, colorless blood or no 

 blood at all). 



DEVELOPEMENT OF SYSTEMATIC ZOOLOGY. 



Pliny. — It is a remarkable fact that after Aristotle, an exclusively 

 systematic direction should have been taken. This is explicable only 

 when we consider that the continuity of investigation was interrupted by 

 the decline and ultimate complete collapse of ancient civilization, and by 

 the triumphant advance of Christianity. The decay is seen in the writings 

 of Pliny. Although this Roman scholar was long lauded as the foremost 

 zoologist of antiquity, he is now given the place of a not even fortunate 

 compiler, who collected from the writings of others the accurate and 

 the falmlous indiscriminately, and re])laced the natural classilication 

 according to structure by the unnatural division according to the place 

 of abode (flying animals, land animals, water animals). 



Zoology of the Middle Ages. — The rise of Christianity resulted in 

 the complete annihilation of science and investigation. Then came a 

 time when answers to questions capable of solution l)y the simplest obser- 

 vation were sought Ijy rummaging of the works of standard authors. 

 How many teeth the horse has, was debated in man}' jxilemics, which 

 would have led to bloodshed if one of the autli<n-s had not tluiught 

 to look into a horse's mouth. Significant of liiis mental bias which 

 prevailed throughout the entire Middle Ages is the 'Physiologus' or 

 'Bestiarius,' from which the zoological authors of the Middle Ages 

 drew much material. The book in its \aiious editions names about 

 seventy animals, among them many creatures of -fakle: the tlragon, 

 the unicorn, the plnenix, etc. Most of the accounts given of 

 various animals are fcLliles intended to illustrate religious or ethical 

 teachings. There are indeed, excci)lions to this general characteristic of 



