Characters, Hereditary and Acquired. 99 



last edition of the Origin of Species. I called the 

 principle the Cessation of Selection— which I still 

 think a better, because a more descriptive, term 

 than Panmixia ; and at that time it appeared to me, 

 as it now appears to Weismann, entirely to supersede 

 the necessity of supposing that the effect of disuse is 

 ever inherited in any degree at all. Thus it raised 

 the whole question as to the admissibility of La- 

 marckian principles in general ; or the question on 

 which we are now engaged touching the possible 

 inheritance of acquired, as distinguished from con- 

 genital, characters. But on discussing the matter 

 with Mr. Darwin, he satisfied me that the larger 

 question was not to be so easily closed. That is to 

 say, although he fully accepted the principle of the 

 Cessation of Selection, and as fully acknowledged 

 its obvious importance, he convinced me that there 

 was independent evidence for the transmission of 

 acquired characters, sufficient in amount to leave 

 the general structure of his previous theory unaffected 

 by what he nevertheless recognized as a factor which 

 must necessarily be added. All this I now mention 

 in order to show that the issue which Weismann 

 has raised since Darwin's death was expressly con- 

 templated during the later years of Darwin's life. 

 For if the idea of Panmixia — in the absence of which 

 Weismann's entire system would be impossible — 

 had never been present to Darwin's mind, we should 

 have been left in uncertainty how he would have 

 regarded this subsequent revolt against what are 

 generally called the Lamarckian principles 1. 



Moreover, in this connexion we must take par- 



' Appendix I. 

 H 2 



