428 ON SUPPOSED BOTANICAL PROOFS OF [VII. 



years. Darwin some time ago pointed out in his work upon 

 ' The Variation of Animals and Plants under Domestication,' 

 that, in the case of the pansy and all other ' improved ' garden 

 flowers, the wild form remained unchanged for many genera- 

 tions after its transference to the garden, apparentl}' un- 

 influenced by the new conditions of life. At length single 

 varieties began to appear, and these were further developed by 

 artificial selection and appropriate crossing, into well-marked 

 races distinguished by peculiar colours, forms, etc. 



In these cases also, changes in the germ-plasm are the first 

 results of the new conditions, and there is no evidence for 

 the occurrence of acquired characters, using the term in its 

 restricted sense. 



I now come to the last botanical fact brought forward by 

 Hofi'mann in support of the transmission of acquired characters. 

 He states that specimens of Solidago virganrea brought from 

 the Alps of the Valais, commenced flowering in the botanical 

 garden at Giessen, at a time which differed by several weeks 

 from that at which specimens from the surrounding country, 

 planted beside them, began to flower. In other words, the time 

 of flowering must have been fixed by heredity in the alpine 

 Solidago, for the external conditions would have favoured a 

 time which was simultaneous with that of the Giessen plants. 



What conclusions can be drawn from these facts ? Hoffmann 

 of course sees in them the proof of the transmission of acquired 

 characters, but this presupposes that the time of flowering was 

 originally an acquired character. Hoffmann indeed appears to 

 entertain this opinion when he somewhat vaguely states that 

 the time at which flowering begins has been acquired by 

 accommodation — that is by the influence of climate — during a 

 long series of generations, and has become hereditary. But 

 what does Hoffmann mean by 'accommodation'? He presum- 

 ably means that which, since the appearance of Darwin's 

 writings, has been generally called adaptation : — that is a 

 purposeful arrangement, suited to certain conditions. The 

 majority of biologists have followed Darwin in believing that 

 such adaptations have been produced by processes of natural 

 selection. Hoffmann seems to imagine that they have arisen 

 in some other way : perhaps he believes, with Nageli, that 

 they have been directly produced by external influences. 



