No. G03] 



BUD-VARIATION 



131 



of Weismann are usually experimentalists whose evi- 

 dence is indeed direct, but often questionable, usually- 

 capable of various interpretations, and always fragmen- 

 tary. I have been bold enough to grasp both horns of 

 the dilemma, and to plead that each is right from his point 

 of view. My confession of faith is, the environment has 

 been an immense factor in organic evolution, but its 

 effects are shown either so infrequently or after the elapse 

 of so great a time, that for the practical purposes of 

 plant breeding we can neglect it as we would neglect an 

 infinitesimal in a calculation. As Bergson, I think, said : 



A few words will make clear the general arguments in 

 favor of this position, although adequate support to the 

 thesis would require considerable time. 



In the first place, it seems to me the possibility of the in- 

 heritance of acquirements must be admitted. Weismann's 

 general contention that the chromatin of the germ-cells 

 is the actual hereditary substance, and that the germ-cells 

 themselves may be regarded as one-celled organisms re- 

 ])roducing by fission and conjugating at certain times, 

 while the body must be considered simply an appendage 

 thrown off from and independent of the germ-cells, is not 

 supported merely by the embryological researches of 

 Boveri, Kahle and Hegner on two or three animal forms, 

 or by the ingenious ovarian transplantations made by 

 Castle and Phillips on guinea pigs, but by all of the recent 

 pedigree culture and cytological genetic work, botanical 

 as ^ell as zoological. Nevertheless it has not been and 

 logically can not be proven that there is no way for en- 

 ^•i^on])^ontal forces to produce germ-plasmic changes, 

 ^rciiioi y is just as strange a phenomenon and Semon has 

 done ])i()lo<ry a service by pointing out the analog}^ be- 

 tween tlie mechanical requirements for memory and for 

 the inheritance of somatic modifications. 



This possibility being admitted, one may well concede 

 the plausibility of the arguments of the numerous pale- 



