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 AlgcB, 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 cer- 

 tain 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 with 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 cir- 

 cumstances, 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 



