THE SCALE OF NATURE 45 



gradations among them. The gradation, shrews, 

 monkeys, apes, man, is not very far from a real genea- 

 logical succession, confirmed by structural and his- 

 torical proofs. The gradation, fish, whale, sheep, on 

 the other hand, though it seemed equally plausible to 

 early speculators, is not confirmed by structure and 

 history. In the age of Aristotle and for long after- 

 wards the ostrich was believed to be a connecting link 

 between birds and mammals, because it possessed, in 

 addition to obvious bird-like features, a superficial 

 resemblance to a camel (long neck, speed in running, 

 desert haunts, and a rather imaginary resemblance 

 in the toes). Sedentary, branching zoophytes were 

 quoted as intermediate between animals and plants ; 

 corals and barnacles as intermediate between animals 

 or plants and stones. Aristotle was convinced of the 

 continuity of nature ; his scale of being extended from 

 inanimate objects to man, and indicated, as he thought, 

 the effort of nature to attain perfection. Malpighi 

 traced analogies between plants and animals, identify- 

 ing the seed and egg, as many had done before him, 

 assuming that viviparous as well as oviparous animals 

 proceed from eggs, and comparing the growth of metals 

 and crystals with the growth of trees and fungi. 

 Leibnitz believed that a chain of creatures, rising by 

 insensible steps from the lowest to the highest, was a 

 philosophical necessity. Buffon accepted the same 

 conclusion, and affirmed that every possible link in the 

 chain actually exists. Pope reasoned in verse about a 

 "vast chain of being," which reaches from God to man, 

 and from man to nothing. The eighteenth century was 

 filled with the sound. 



Bonnet in 1745 traced the scale of nature in fuller 

 detail than had been attempted before. He made 



