NECESSARY TRUTHS— EFFECTS OF EXPERIENCE. 685 



degeneration is unquestionably a disease whose original 

 causes are unknown ; and like other ' accidental variations ' 

 it is hereditary. But it ultimately ends in sterility ; and it 

 seems to me quite unfair to draw any conclusions from its 

 natural history in favor of the transmission of acquired 

 peculiarities. Nor does the degeneration of the children of 

 alcoholics prove anything in favor of their having inherited 

 the shattered nervous system which the alcohol has induced 

 in their parents : because the poison usually has a chance 

 to directly affect their own bodies before birth, by acting 

 on the germinal matter from which they are formed whilst 

 it is still nourished by the alcoholized blood of the parent. 

 In many cases, moreover, the parental alcoholics are them- 

 selves degenerates neurotically, and the drink-habit is only 

 a symptom of their disease, which in some form or other 

 they also propagate to their children. 



There remain the inherited mutilations of the guinea- 

 pig. But these are such startling exceptions to the ordinary 

 rule with animals that they should hardly be used as ex- 

 amples of a typical process. The docility of domestic 

 cattle is certainly in part due to man's selection, etc., etc. 

 In a word, the proofs form rather a beggarly array. 



Add to this that the writers who have tried to carry out 

 the theory of transmitted habit with any detail are always 

 obliged sometvhere to admit inexplicable variation. Thus 

 Spencer allows that 



" Sociality can begin only where, through some slight variation, there 

 is less tendency than usual for the individuals to disperse. . . . That 

 slight variations of mental nature, sufficient to initiate this process, may 

 be fairly assumed, all our domestic animals show us: differences in their 

 characters and likings are conspicuous. Sociality having thus commenced, 

 and survival of the fittest tending ever to maintain and increase it, it 

 will be further strengthened by the inherited effects of habit.'* Again, 

 in writing of the pleasure of pity, Mr. Spencer says : " This feeling is 

 not one that has arisen through the inherited effects of experiences, but 

 belongs to a quite different group, traceable to the survival of the fittest 

 simply — to the natural selection of incidental variations. In this group 

 are included all the bodily appetites, together with those simpler in- 

 stincts, sexual and parental, by which every race is maintained ; and 

 which must exist before the higher processes of mental evolution can 

 commence." t 



*Priuc. of Psychol., ii. 561. f Ibid. p. 623. 



