Classification of Animals. 13 



according to their habits fish of the sea, birds of the 

 air, beasts of the earth, and things under the earth; 

 as carnivores, herbivores, and omnivores; Physlological 

 and it is not very long since even expert ciassifica- 

 ornithologists classified birds as waders tlon ' 

 and divers, climbers and scratchers, and so on. This 

 mode of classification is always as interesting as it is 

 natural, but its value is disqounted by the fact that 

 similarity of habit or habitat does not necessarily imply 

 natural affinity. Bats are not birds because they fly in 

 the air, nor whales fishes because both live in the sea. 



The first great step to a more technical, and there- 

 fore truer, classification was made by Aristotle (384- 

 322 B.C.), for his grouping was based on 

 similarities of structure. Although he did 

 not tabulate a classification as such, he was the first to 

 draw that useful, but now somewhat hazy, line between 

 the backboned and the backboneless, between the 

 "lower" and "higher" animals. Thanks in part to 

 the specimens which his pupil Alexander sent him, 

 he knew about 500 different animals far more, if one 

 pauses to count, than most of us can even name, and, 

 although he made the mistake of regarding the back- 

 boneless animals as bloodless, his classification reveals 

 the insight of the true taxonomist. 



Aristotle's outline remained practically unaltered for 

 eighteen centuries, the first to modify it to any purpose 

 being Wotton (1492-1555), a London physi- R ay and 

 cian, who published a work, De Differentiis Linnaeus. 

 Animalium, in 1552, and introduced a large but hetero- 

 geneous group of zoophytes. The encyclopaedists, such 

 as Gesner, Johnstone, and Aldrovandi, added consider- 

 ably to the list of known forms, but made no improve- 

 ments of moment in their classification. Of importance, 

 however, was the work of John Ray (1628-1705), the 

 worthy predecessor of Linnaeus. He was the first to 

 define the use of the term "species", and to lay 

 emphasis on anatomical characteristics as a basis of 

 classification. For these reasons he may, as Professor 

 Ray Lankester observes, be considered "the father of 

 modern zoology". 



