444 



KINSHIP AND .\;).VP'rATI()\ 



It has l)ecn thought l)y many luituraHsts that the differ- 

 ences among plants and anim:ils may best lie accounted for 

 as peculiarities which have arisen in individual acquire- 

 ments, these having become hereditary and thus characteris- 

 tic after many generations of similar response to a similar 

 environment. Suppose, b\' way of example, that some of 

 the seedlings from jirimitive marsh-marigolds grew in a 

 rather dry locality and were more or l(\ss shaded by o\'er- 

 growth. Thej' might be expected to respond to the lessened 

 light by elongation of the internodes and leaf-stalks, while a 



Fig. 302. — Pigmy Buttercup {Tinnuiin,hi< itiiijiiKnix, Oowfoot Family, 

 Ranmiculacew) . Plant. Mowit. l'"niU. (Hrittou ;iiid Brown.) — 

 Peroiniial (?) herb 5-112 cm. t:\ll; (Imvcrs yellow; fruit dry. Native 

 home; northern .Vnierica an(.l Eurasia. 



finger-like lolling of the blades through increased growth along 

 the ribs and scant growth of the pulp lietween the stem 

 would be fortunate as enabling the heaves to catcli more of 

 what little light there was. But the less favorable contlitions 

 for food-making would render it iinpossibl(> for tliem to form 

 and feed as many seeds as the marsh plants had done; hence 

 some of the later-formetl ovules would be more or less star\-ed. 

 From the good seeds formed by these ]iioncer plants and 

 scattered in the \icini<y, a secontl generation would arise, 

 the individuals of whicli A\'ouId respond similarly to the same 

 trying conditions. Innumei-ablc gencialions might follow, 



