THE SOLID COMPONENTS OF PLANTS. 22? 



leaf-stalk of the Artichoke, in which they have a some- 

 what tubular appearance; and by the stretching; of 

 the membrane, the pores, which in the hexagonal 

 cells are arranged without any order, are now very 

 regularly disposed. The cells are proportionally 

 more abundant in herbaceous plants than in trees ; and 

 in the younger than in the older branches. 



Such is the nature and appearance of the cellular 

 texture. There is every reason for believing that it 

 enters as a component into almost every part of the 

 vegetable structure ; and anatomy confirms the opin- 

 ion as far as we have the means of ascertaining the 

 fact. There are indeed some plants, as the Fuci and 

 other marine vegetables which appear to be altogeth- 

 er composed of cellular texture. 



The Vascular texture is the next of the solids enu- 

 merated. It consists of hollow tubes of different 

 forms and structure, which are capable, like the ves- 

 sels of the animal frame, of conveying fluids. When 

 a succulent stem is cut transversely fluids are seen 

 issuing from different points ; and, if the peculiar juices 

 of the plant be of a milky or colored nature, as in the 

 Fig tree, or in any of the species of the genus Eu- 

 phorbia, they are still more clearly perceived to issue 

 from different points ; for instance, the watery or col- 

 orless from one set, and the milky or the colored from 

 anodier. This circumstance leads us to conclude 

 that the sap, or watery fluid imbibed from the soil, is 

 carried in one set of vessels, and that the proper juices 

 formed from the sap by the vital powers of the plant, 

 are conveyed in another ; or, that there are conducting 

 and returning vessels, a fact which has been proved 

 by experiment. 



The minuteness of these vessels requires the aid of 

 the microscope for their examination ; and even by 

 its assistance as they are not easily seen, owing to 



