VEGETABLE ABSORPTION. 19 



§ 2. Absorption of Nutriment by Plants. 



The greater number of cellular plants absorb 

 water with nearly equal facility from every part 

 of their surface : this is the case with the Algce, 

 for instance,which are aquatic plants. In Lichens, 

 on the other hand, absorption takes place more 

 partially ; but the particular parts of the surface 

 where it occurs are not constantly the same, and 

 appear to be determined more by mechanical 

 causes than by any peculiarity of structure : 

 some, however, are found to be provided in certain 

 parts of the surface with stomata, which De 

 Candolle supposes may act as sucking orifices. 

 Many mushrooms appear to be capable of ab- 

 sorbing fluids from all parts of their surface 

 indiscriminately ; and some species, again, are 

 furnished at their base with a kind of radical 

 fibrils for that purpose. 



In plants having a vascular structure, which 

 is the case in by far the greater number, the 

 roots are the special organs to which this office 

 of absorbing nourishment is assigned : but it 

 occasionally happens that, under certain circum- 

 stances, the leaves, or the stems of plants are 

 found to absorb moisture, which they have been 

 supposed to do by the stomata interspersed on 

 their surface. This, however, is not their natural 

 action ; and they assume it only in forced situa- 



