348 ELEMENTARY ORGANS. CHAP. III. 



SECTION I. 



Utricles. 



Descrip- THE Utricles are the fine and membranous vessels 

 constituting the cellular tissue of the pith and pulp 

 already described, whether of the plant, flower, or 

 fruit. Individually they resemble oblong bladders 

 inflated in the middle, as in the case of some plants ; 

 or circular, or hexagonal cells, as in the case of 

 others. Collectively they have been compared to 

 ~an assemblage of threads of contiguous bladders or 

 vesicles, or to the bubbles that are found on the sur- 

 face of liquor in a state of fermentation. 

 As exist- But this^ description is applicable to them only as 

 herbs. they occur in herbaceous plants, or in the soft and 

 tender parts of woody plants ; though in either case 

 they are not always of the same figure in all the dif- 

 ferent parts of the same plant. In the leaf-stalk of 

 the Artichoke, for example, their diversity of figure 

 is very conspicuous, presenting, in their free and 

 uncompressed state, whether on a horizontal or 

 longitudinal slice, a beautiful assemblage of hexa- 

 gonal cells ; but in their crowded and condensed 

 state, as they approximate the longitudinal fibres, 

 an assemblage of tubular threads successively in- 

 flated and contracted. In woody plants their diver- 

 sity of figure is still greater, as must appear evident 

 if it is but recollected that they constitute not only 



