238 MODERN IDEAS OF EVOLUTION 



superficial view, not reaching to the actual origin of varietal 

 difference. If Weismann is right, we can no longer speak 

 of an herbivorous quadruped as making efforts to reach food 

 above its head, and so acquiring a tendency to elongation of 

 neck which may be transmitted to its offspring, so that they 

 may become giraffes. Nor can we be content merely to 

 suppose an accidental elongation in one individual to give it 

 such advantage in the struggle for existence as to cause it 

 alone to survive in times of scarcity, and to propagate its 

 kind. Such suppositions must be altogether gratuitous and 

 trifling, and we must look for deeper causes capable of 

 affecting the germinal matter, if we wish to establish the pos 

 sibility of such changes. At present, as already hinted, the 

 only causes of this kind certainly known in higher animals 

 are those of a psychical character, and this is perhaps one 

 reason of the liability of the more intelligent and shifty 

 animals to varietal change. The similar capacity of some 

 animals low in the scale may depend merely on the wider 

 scope of vital work in less differentiated organisms, or on the 

 greater liability of the whole organism to be affected by any 

 change. 



Whatever may be the ultimate amount of acceptance of 

 these remarkable and ingenious views of the German physio 

 logist, they no doubc open a vista which extends far beyond 

 the crude ideas of evolution at present current. 



It is farther to be observed in this connection that the 

 discussions above referred to relate to variation rather than 

 to origin of species, that they do not establish any hard-and- 

 fast line separating congenital from acquired characters, and 

 that they strongly emphasise the objections against mere 

 accident as a cause of variation, and show the necessity, in 

 order to the origin and perpetuation of varieties, not merely 

 of one change, but of many correlated changes. They also 

 show that the changes supposed must take place by anticipa- 



