278 VEGETABLE ORGANOGRAPHY. 



the organs of plants, and their presence determines the 

 possibility of the development of certain parts. In fact, 

 without this deposit prepared before-hand, it would be 

 impossible to understand how certain ascending parts are 

 nourished until the period when their own nourishing 

 organs are developed, or how certain parts are developed 

 although apparently devoid of proper organs to elaborate 

 the ascending sap. 



If I form a just idea of this phenomenon, which is in 

 itself very remarkable, this is how I understand it : the 

 watery sap or lymph absorbed by the roots passes 

 through the cellular tissue essentially by the intercel- 

 lular passages, as Kieser and others appear to have 

 clearly demonstrated ; when it passes into the canals or 

 passages which separate the very long cellules, which 

 are usually empty, it follows its course without any 

 alteration; when it traverses the organs abundantly 

 supplied with round cellules, its motion nearly ceases, 

 or is very slow, and then another phenomenon may take 

 place : if the progress of the vegetation of the preceding 

 year has accumulated in these cellules a certain quan- 

 tity of mucilage, this is partly or wholly dissolved in the 

 lymph which surrounds the cellules, and when, by the 

 development of the upper parts, this lymph is attracted 

 there, it does not arrive in the state of pure water, but 

 it contains a certain quantity of mucilage in solution. 



I think that the same takes place with regard to fecu- 

 lent or oily matters, although we do not possess, espe- 

 cially as concerns the former, any correct ideas of the 

 manner in which they can be affected by the water so as 

 to become soluble in it. Although we do not know 

 how to render fecuia or starch soluble except by pro- 

 cesses hardly likely to be met with in vegetation, it is, 

 however, certain that it becomes so by the force alone 

 of vegetable life, and the history of the germination of 



