112 DARWINIAN INTERESTS 



are not only transmitted by the one cell, but diffused there- 

 after throughout the future individual. It is so hard to 

 conceive this, or rather to grasp this, for individuals, that 

 when you come to extend it to species, genera, orders, classes, 

 &c, it may very well form a stumblingblock to the accepta- 

 tion of the * Development of Species Doctrine ' — as it did 

 with me. 



So far I have instinctively held your doctrine but never 

 as a postulated or formulated theory or hypothesis — it was 

 merely as part of the doctrine of descent, the most ordinary 

 phenomena of descent being simply inconceivable to me 

 without it. Much less did I ever ask myself whether the 

 most obscure facts of reproduction were explicable on any 

 other hypothesis. 



So far we are agreed ; when you come to your atoms and 

 germs and gemmules and so forth we do not part company, 

 but move off a little — I do not see my way. Tyndall believes 

 he feels atoms, as firmly as St. Paul believed he saw Christ. 1 

 I do not say that atoms do not exist, but I rather suppose 

 that they may be like minutes of time or inches of space 

 or any other 'purely arbitrary quantities. Your doctrine of 

 atoms thrown off in no way furthers my perceptions or 

 advances my ideas. 



I have again read Part I. of Pan. and with literally re- 

 newed delight. I do think Pan. as fine a thing as you ever 

 writ, the idea of germs and atoms notwithstanding. As to 

 [my] laying claim to having by any logical process or reasoning 

 arrived at such a doctrine, in any scientific sense, i.e. by 

 testing it as you have done, do not for a moment entertain 

 it. I always held, as part and parcel of the development 

 doctrine, that the potentiality of the parent was not only 

 transmitted by a cell, but indefinitely diffused therefrom, 

 and hence, as I told you from the first, I could not see what 

 there was new in your theory, except the idea of atoms, &c, 

 which I could not grasp. 



To Asa Gray 



March 12, 1868. 



Have you read Darwin's last book, and what do you 

 say to Pangenesis ? I have gone deeply into the whole 

 philosophy of the Subject — there then. 



1 Cp. p. 359. 



