180 THE VARIATION OF ANIMALS IN NATURE 



homozygous for their distinctive characters. Nevertheless 

 we have shown that ' specificity ' may be a deeply seated 

 property of the organism, and that the facts of development 

 argue a close connection between the parts of the organism 

 and an interdependence from which even the more superficial 

 character expressions could hardly be expected to escape. 

 There is some risk, it is true, in exaggerating the degree of this 

 dependence, and we should remember that progressive eman- 

 cipation and self-sufficiency of the parts which Jenkinson 

 {I.e. p. 1 68) has described. 



The question which we have to face is — are the complexes 

 of specific characters in their ultimate genetic representation 

 simply fortuitous mosaics associated either by the mechanism of 

 heredity or by the coincident effects of selection or environment, 

 or are they bound together more intimately by the organic 

 association seen in development ? It is highly doubtful whether 

 we know enough about the basis of specific characters to come 

 to any decision. Such evidence as we have certainly suggests 

 that the association is, on the whole, fortuitous. If this view 

 is ultimately found to be correct, a general question of some 

 importance is raised, and that is — how does it come about that 

 some parts are more independent of the general organisation ? 

 We might suggest that specific and racial characters, being 

 newly acquired, have not yet been incorporated in the general 

 unity of the organism and have not yet attained that closeness 

 of association and mutual dependence that is found in other 

 parts. How such dependence has arisen, and how exactly the 

 accretions produced by new evolutionary steps have their 

 association transformed from a fortuitous to a permanent 

 basis, is a matter which it does not yet seem possible to 

 discuss (cf. Chapter X, p. 370). 



