26 THE EVOLUTION OF MAN. 



There is no doubt that Man is descended from an extinct 

 mammalian form, which, if we could see it, we should 

 certainly class with the Apes. It is equally certain that 

 this primitive Ape in turn descended from an unknown 

 Semi-ape, and the latter from an extinct Pouched Animal. 

 But then it is beyond a doubt that it is only in respect of 

 essential internal structure, and on account of their similarity 

 in the distinctive anatomical characters of the order, that all 

 these extinct ancestral forms can be spoken of as members 

 of the yet extant mammalian orders. In external form, in 

 generic and specific characters, they must have been more or 

 less — perhaps even greatly — different from all living repre- 

 sentatives of the orders to which they belonged. For it 

 must be accepted as a quite universal and natural fact in 

 phylogenetic evolution that the parent-forms ' themselves, 

 with their specific characters, became extinct at a more or 

 less distant period. Those extant forms which come nearest 

 to them, yet differ from them more or less, perhaps even 

 very essentially. Hence in our phylogenetic researches 

 and in our comparative view of the still living divergent 

 descendants aU we can undertake to do is to determine 

 how far the latter depart from the parent-form. We may 

 quite confidently assume that no single older parent-form 

 has reproduced itself without modification down to our time. 



We find this same state of things on comparing various 

 extinct and living languages, which have sprung from one 

 common primitive tongue. If, from this point of view, we 

 examine the genealogical tree of the Indo-Germanic 

 languages, we may conclude, on d priori grounds, that all 

 the earlier primitive languages, fundamental languages, and 

 ancestral languages, from which the living dialects are 



