EXFERIMKXTAI. MORPHOLOGY I 53 



book the theoretical treatment deals mainly with nutrition. 



The lenji;th of time and the number and nature of the steps 



involved in the process of preparation for fruiting are thus 



related to the amount and character of the various organic 



and inorganic foodstuffs present in the plant, and it is 



suggesteci that the relation of organic to inorganic substances 



may often control the activities of the latter. In the case of 



a Cocos seedling which developed an inflorescence when only 



a few primary leaves had been formed, it is pointed out that 



the omission of the long normal period of preparation for 



flowering, — with the large stem, numerous compound leaves 



et cetera, — may ha\e been ciue to a lack of water and salts, 



so that the ratio of organic to inorganic materials may have 



approached, in this seedling, the magnitude normally reached 



only after the manufacture of a large quantity of organic 



foodstuffs. Also, it appears that Cumpaiuihi rotnudifol'ui 

 forms round lea\es when the ratio of organic to inorgani-j 



material is small, and that the linear leaves appear only 



after this ratio has been increased by the manufacture of 



more organic substances. 



In the more complex and difficult subjects of heterophylly 

 correlation, and regeneration, which are treated to consid- 

 erable length in this book, the same idea is expressed from 

 time to time, namely that these mysterious phenomena are 

 dependent primarily upon nutrient conditions within the 

 plant, which may often he altered by a change in the environ- 

 mental factors. The most valuable feature of the discussions 

 of these difficult subjects lies perhaps in the clear descriptions 

 of the cases themselves and in the logical statement of the 

 general conditions under which the difterent phenomena 

 seem to occur, without any attempt to express hypotheses 

 regarding the deeper causal factors. Deeper theorizing 

 may come with greater knowledge, it is at present well to 

 hold clearly in mind the facts of the various cases as they 

 actuallv occur. 



