ENVIRONMENT AND EVOLUTION — KROPOTlvlN, 419 



With regard to the former I have already mentioned in a previous 

 article 1 that Darwin, who had studied the subject, had shown that 

 there is no means of finding any substantial distinction between re- 

 production by buds, cuttings, rootstocks, and the like, and reproduc- 

 tion by seed. The laws of both are the same, and in both cases the 

 reproduction takes place by means of germ cells, capable of reproduc- 

 ing the whole plant with its sexual organs and with sexual reproduc- 

 tion, whether the germ plasm be contained in a seed or a bud, in the 

 leaf of a begonia, or in the cambial tissue of a willow. And I have 

 also shown that if Weismann, writing in 1888 under the fascination 

 of his amphimixis hypothesis, made the grave mistake of thinking 

 that there is no transmission of germ plasm in vegetative reproduc- 

 tion, and therefore described " bud-variation " as an " individual 

 variation," he at least saw his error later on. He recognized in 

 1904. 2 using almost the same words as Darwin used in Variation, 

 that a plant obtained through budding is as much a new individual as 

 if it had been reproduced by seed. 3 



But it must be remembered that in the vegetable world reproduc- 

 tion by buds (rootstocks, runners, and the like) is far more impor- 

 tant than reproduction by seed. In fact, it seems most probable 

 that the immense majority of the plants which cover the northern 

 part of the northern hemisphere have reproduced themselves since 

 the glacial period chiefly by buds, runners, rootstocks and the like, 

 as the Arctic and many Alpine plants still reproduce themselves. 

 And as they transmitted to their offspring, during this long period 

 of a chiefly vegetative reproduction, the characters they acquired in 

 new surroundings, as they followed the retreat of the ice sheet, we 

 can already say that an enormous number of sub-Arctic and Tem- 

 perate Zone varieties and species owe their origin to the inherited 

 effect of the direct action of changing surroundings. 



It is very nice to say in poetical language that the steppes of south 

 Russia are covered now with the same individuals of grasses that 

 were withering under the hoofs of the horses during the migration 

 of the Ugrians from the southern Urals to Hungary ; but a botanist 

 who knows that a bud on the rootstock of a grass contains the very 

 same germplasm as the seed in its ear does not take these pretty 

 images for a scientific induction. 



1 Nineteenth Century and After, October, 1914 ; pp. 821-825. 



2 Vortrage, 2d edition, vol. ii, pp. 1 and 29. 



3 WeismanD is thus no longer responsible for those who go on repeating his opinions of 

 1888, when he believed that in vegetative reproduction we have only a subdivision of the 

 same individual, and added " But no one will doubt that one and the same individual can 

 be gradually changed during the course of its life by the direct action of external influ- 

 ences." (Essays, i, 420.) 



