XVI] THE PROBLEM OF PHYLOGENY 715 



It would seem to me that the mechanical principles and 

 phenomena which we have dealt with in this chapter are of no small 

 importance to the morphologist, all the more when he is inclined 

 to direct his study of the skeleton exclusively to the problem of 

 phylogeny; and especially when, according to the methods of 

 modern comparative morphology, he is apt to take the skeleton 

 to pieces, and to draw from the comparison of a series of scapulae, 

 humeri, or individual vertebrae, conclusions as to the descent 

 and relationship of the animals to which they belong. 



It would, I dare say, be a gross exaggeration to see in every 

 bone nothing more than a resultant of immediate and direct 

 physical or mechanical conditions ; for to do so would be t® deny 

 the existence, in this connection, of a principle of heredity. And 

 though I have tried throughout this book to lay emphasis on the 

 direct action of causes other than heredity, in short to circum- 

 scribe the employment of the latter as a working hypothesis in 

 morphology, there can still be no question whatsoever but that 

 heredity is a vastly important as well as a mysterious thing; it 

 is one of the great factors in biology, however we may attempt to 

 figure to ourselves, or howsoever we may fail even to imagine, 

 its underlying physical explanation. But I maintain that it is 

 no less an exaggeration if we tend to neglect these direct physical 

 and mechanical modes of causation altogether, and to see in the 

 characters of a bone merely the results of variation and of heredity, 

 and to trust, in consequence, to those characters as a sure and 

 certain and unquestioned guide to affinity and phylogeny. 

 Comparative anatomy has its physiological side, which filled 

 men's minds in John Hunter's day, and in Owen's day ; it has its 



from the sum of its parts in the case of the organism: "The organism, we know, 

 is a system the single constituents of which are inorganic in themselves ; only the 

 whole constituted by them in their typical order or arrangement owes its specificity 

 to 'Entelechy'" {Gifford LerAures, p. 2"?9, 1908): and I think it could be shewn 

 that many other philosophers have said precisely the same thing. So far as the 

 argument goes, I fail to see how this Entelechy is shewn to be peculiarly or 

 specifically related to the living organism. The conception that the whole is 

 ahvays somethini^ very different from its parts is a very ancient doctrine. The 

 reader will perhaps remember how, in another vein, the theme is treated by Martinus 

 Seriblerus: "In every Jack there is a meat-roasting Quality, which neither resides 

 in the fly, nor in the weight, nor in any particular wheel of the Jack, but is the 

 result of the whole composition; etc., etc." 



