INDIVIDUAL ADJUSTABILITY 41 



Mr. Francis Darwin may be briefly discussed. 

 It is well known that plants have the power of 

 adjusting themselves to their individual environ- 

 ment, and that such adjustment may beneficially 

 take the place of a rigid speciahzation. The fixed 

 condition of plants renders this power especially 

 necessary for them, and the hereditary trans- 

 mission of the results of its exercise especially 

 dangerous. Where the seed falls, there must 

 the plant grow. The parent was limited to one 

 out of many possible environments ; the offspring 

 may grow in any of them, and for one that would 

 hit off the precise conditions of the parent and 

 would benefit by inheriting the parental response, 

 numbers would have to live in different surround- 

 ings and might be injured by the hereditary bias. 



Mr. Francis Darwin calls attention to the leaves 

 of the beech, which in the interior shaded parts 

 of the tree possess a structure different from that 

 exhibited on the outer parts more freely exposed 

 to light. The structure of the shaded leaves 

 resembles that apparently stereotyped in trees 

 always adapted to shade, and Mr. Francis Darwin 

 is inclined to regard the permanent condition as 

 a final result of the hereditary transmission of 

 the same response through a large number of 

 generations. 



The development of shade foliage in the beech 

 is, I presume, a manifestation of a power widely 

 spread among animals and probably among plants 

 also — a power of producing a definite individual 



