CHAP. xxiv. SYSTEMS OF CLASSIFICATION. 473 



of the inferior animals? We certainly cannot escape from 

 such a conclusion without abandoning many of the weightiest 

 arguments which have been urged in support of variation 

 and natural selection, considered as the subordinate causes 

 by which new types have been gradually introduced into the 

 earth. Many of the gaps which separate the most nearly 

 allied genera and orders of mammalia are, in a physical 

 point of view, as wide as those which divide man from the 

 mammalia most nearly akin to him, and the extent of his 

 isolation, whether we regard his whole nature or simply his 

 corporeal attributes, must be considered before we can discuss 

 the bearing of transmutation upon his origin and place in 

 the creation. 



Systems of Classification. 



In order to qualify ourselves to judge of the degree of 

 affinity in physical organisation between Man and the lower 

 animals, we cannot do better than study those systems of 

 classification which have been proposed by the most eminent 

 teachers of natural history. Of these an elaborate and 

 faithful summary has recently been drawn up by the late 

 Isidore Geoffrey St. Hilaire, which the reader will do well 

 to consult.* 



He begins by passing in review numerous schemes of 

 classification, each of them having some merit, and most 

 of which have been invented with a view of assigning to 

 Man a separate place in the system of Nature, as, for 

 example, by dividing animals into rational and irrational, or 

 the whole organic world into three kingdoms, the human, the 

 animal, and the vegetable, an arrangement defended on the 

 ground that Man is raised as much by his intelligence above 

 the animals as are these by their sensibility above plants. 



* Histoire Naturale Generale des Kgnes organiques. Paris, vol. ii. 1856. 



