6 The Descent of Man 



form of selection, or by the inherited effects of the use and disuse of 

 parts. We know, however, that many strange and strongly marked 

 peculiarities of structure occasionally appear in our domesticated pro- 

 ductions ; and if the unknown causes which produce them were to 

 act more uniformly, they would probably become common to all the 

 individuals of the species.' — Vol. ii. p. 387. 



Mr. Darwin, indeed, seems now to admit the existence of 

 internal, innate powers, for lie goes on to say : — 



* We may hope hereafter to understand something about the causes 

 of such occasional modification, especially through the study of 



monstrosities In the greater number of cases we can only 



say that the cause of each slight variation and of each monstrosity 

 lies much more in the nature or constitution of the organism ^ than in 

 the nature of the surrounding conditions ; though new and changed 

 conditions certainly play an important part in exciting organic changes 

 of all kinds.' 



Also, in a note (vol. i. p. 223), lie speaks of 'incidental 

 results of certain unknown differences in the constitution of 

 the reproductive system.' 



Thus, then, it is admitted by our author that we may have 

 ' abrupt, strongly marked ' changes, ' neither beneficial nor in- 

 jurious ' to the creatures possessing them, produced by ' un- 

 known agencies ' lying deep in ' the nature or constitution of 

 the organism,' and which, if acting uniformly, would ' prob- 

 ably' modify similarly 'all the individuals of a species.' 

 If this is not an abandonment of 'natural selection,' it 

 would be difficult to select terms more calculated to express 

 it. But Mr. Darwin's admissions of error do not stop here. 

 In the fifth edition of his Origin of Species (p. 104) he says : 

 'Until reading an able and valuable article in the I^orth 

 British Review (1867), I did not appreciate how rarely single 

 variations, whether slight or strongly marked, could be per- 

 petuated.' Again: he was formerly 'inclined to lay much 



1 The italics in the quotations from Mr. Darwin's book in this article are, 

 in almost all cases, ours, and not the author's. 



