64 THE ROYAL SOCIETY OF CANADA 



Transitional forms of this kind are never found in nature, at 

 any rate among the mammals. In nature species keep distinct and 

 breed only with their kind. The horse and the ass existed together 

 over a long period of time and never produced a mule by interbreeding 

 till man domesticated and interbred them. Transitional forms 

 blending the characters of two distinct species or families as Pithe- 

 canthropus is thought to blend the characters of man and the anthro- 

 poids, are the product of articifical selection, never of natural selection, 

 and such form could no more exist naturally than did a mule or any 

 other of the hybrids man has brought into existence by the inter- 

 breeding of different species. 



We misread Nature's plan altogether when we see in Pithecan- 

 thropus a "missing link," a "transitional" form linking us up with 

 the anthropoids. Man and the anthropoids are truly related, but 

 not in this way. Their connection lies in their common descent 

 and common ancestry; but when once a divergence had taken place 

 and the two types had become specialised nothing could bring them 

 together again but a retracing of all the steps they had taken; and 

 that course, in the higher foims of life Nature has forbidden. 



It is futile, then, to look for "missing links" and "transitional" 

 forms. We shall never find them ; they do not exist. What we may 

 be lucky enough to find are types of men like Eoanthropus and types 

 of apes like Pilgrim's Sivapithecus or others more closely resembling 

 in their skull forms the young of the present-day apes. Thus far 

 Eoanthropus is the most truly primitive type of man we have yet 

 discovered and the one which most plainly suggests to us the type 

 of being the ancestor common to man and the anthropoids must 

 have been; and Pithecanthropus is the most human-like of the 

 ancient apes we know of. We shall never see Pithecanthropus in 

 the right perspective until we can clear our minds of the misleading 

 notion that in looking for the first man, the really primitive human 

 type, we have to seek for a form suggestive of the anthropoids as we 

 know them today. The anthropoids and man together constitute 

 two diverging lines of evolution sprung from a common source, 

 The numerous anatomical and morphological resemblances between, 

 the two leave no room for doubt on this point. Keith tells us, for 

 example, that man shares with the chimpanzee 396 common characters 

 with the gorilla, 385; with the orangoutang, 272, and with the gibbon, 

 188. It is clear, then, that the farther back we go in their phyletic 

 history the closer will the two lines converge until there comes a 

 time when we shall see no radical difference between them; but that 

 does not at all mean that man will exhibit characters like those of 



