ix.] ORIGIN OF ROOT FORMS 81 



form predominated ; in the country it was the 

 contrary. 



M. Languet de Sivry likewise found that 



" seeds of the short-rooted carrot, when sown 

 in a particular soil in the alluvial deposits 

 formed by a small river in France, yielded 

 immediately during the first generation a 

 number of long-rooted plants, either white or 

 yellow, whose roots were very much larger 

 than those of the parent plants." 1 



These differences in each case are hereditary, 

 for all seed growers can supply their customers 

 according to requirements, and they " come 

 true," sufficiently to be depended upon. 



Another result follows from cultivation. The 

 above plants are annuals when wild, but by grow- 

 ing them in a garden soil the foliage becomes 

 greatly enlarged. The result is that far more 

 starch, sugar, etc., is made than the plant 

 can utilise ; hence the enlargement of the root 

 wherein to store it. Secondly, the vegetative 

 season is much prolonged by the vigorous growth 

 of the soma, so that it cannot flower the same 

 season. Thus they become biennials, and ever 

 after retain that habit. 2 Systematic botanists 

 often distinguish between the annual, biennial, 

 and perennial habits as specific characters. 



1 "Experimental Evolution," by H. de Varigny, quoting from 

 Socitie Eoyale et Centrale d' Agriculture, ser. 2, vol. ii. 1846-7, 

 p. 539. 



2 The beet-root is a wild perennial of England, but is also con- 

 verted into a hereditary biennial. 



L 



