" * * * the «!;('n('ral |)iinci])l('s of tlu; hypothesis of cvohitioii lead to 

 the coiu'hision that the horse must have been derived from some quad- 

 ruped which i)ossessed five complete digits on each foot; which had the 

 ])ones of the forearm and of the leji comj)lete and sej)irate: and which 

 possessed forty-foui- teetli, amont!; whicli the crowns of the incisors and 

 grinders had a simple structure; while the latter gradually increased in 

 size from before backwards, at any rate in the anterioi- part of the 

 s(M'ies. and had short crowns. 



And if the horse has been thus evolved, and the remains of the 

 different stages of its evolution have been preserxed, they ought to 

 jii-esent us with a series of forms in which the number of the digits 

 becomes reduced; the bones of the forearm and leg gradually take on 

 the equine condition; and the form and arrangement of the teeth 

 successively api:)roximate to those which obtain in existing horses. 



Let us turn to the facts and see how far they fulfil these require- 

 ments of the doctrine of evolution." 



Huxley. The Defnonstratire Evidence of Evolution. 



