248 Evolution and Adaptation 



neck without many and great changes of the muscles and 

 bones of the neck and of the fore-part of the body. Unless, 

 for instance, the fore-legs had been also strengthened, there 

 would be failure in fighting and in locomotion. Since " we 

 cannot assume spontaneous increase of all these parts pro- 

 portionate to the additional strains, we cannot suppose them 

 to increase by variations one at once, without supposing the 

 creature to be disadvantaged by the weight and nutrition of 

 the parts that were for a time useless, — parts, moreover, 

 which would revert to their original sizes before the other 

 needful variations occurred." 



The answer made to this argument was that coordinating 

 parts vary together. In reply to which Spencer points to 

 the following cases, which show that this is not so : The 

 blind crayfish in the Kentucky caves have lost their eyes, 

 but not the stalks that carry them. Again, the normal 

 relation between the length of tongue and of beak in some 

 varieties of pigeons is lost. The greater decrease in the 

 jaws in some species of pet dogs than of the number of 

 their teeth has caused the teeth to become crowded. 1 " I 

 then argued that if cooperative parts, small in number, 

 and so closely associated as these are, do not vary together, 

 it is unwarrantable to allege that cooperative parts, which are 

 very numerous and remote from one another, vary together." 

 Spencer puts himself here into the position of seriously main- 

 taining that, because some cooperative parts do not vary to- 

 gether, therefore no cooperative parts have ever done so, and 

 he has taken this position in the face of some well-known 

 cases in which certain parts have been found to vary together. 



In this same connection Spencer brings up the familiar 

 pike de resistance of the Lamarckian school, the giraffe. He 

 recognizes that the chief traits in the structure of this animal 

 are the result of natural selection, since its efforts to reach 



1 It is curious that Spencer does not see that this case is as much against his 

 point as in favor of it, since the unused teeth did not also degenerate. 



