INDEX. 359 



ly distinguishable by the form of the fruit; examples 



18, 79, 19, 20 

 cultivated for diet . . . . 20; 80 



V. 



Vallisneria, the character of ... 207 



Vascular structure, scarcely traceable in Fungi and Lich- 

 enes ...... 283 



visible, however, in Marchaniia, and formed of a 



single porous anastomosing tube closely connected 

 with the cellular matter .... 284 



nearly similar, as above, in Mosses ib. 



Vascular texture, what. — 2 sets of vessels for the ascent and 



descent of the vegetable fluids . . . 227 



rendered more visible by imbibing colored fluids — 



how to perform the experiment; with examples — the 

 vessels or tubes mutually anastomose . . 228 



they vary in size and structure . . 229 



3 principal kinds, viz. . . . ib. 



Vessels Entire, or simple imperforate cylinders — 



collected in clusters — how examined — their office to 

 convey the proper juices of the plant . . ib. 



Vessels perforated, of 2 kinds ; viz. Cribriform 



or porous; sometimes moniliform, where found 229,230 



annular vessels, formed of parallel attached rings 230 



where found ; both kinds some- 

 times occur in the same tube . . . 231 



Vessels spiral, or tracheal of authors . ib. 



the improbability of their vascular 



structure. — Found in the medullary sheath of young 

 shoots of trees, &ic. in the centre of the ligneous 

 threads of the stems and leaves of Grasses, Palms, and 

 Liliaceous plants, &c. .... 232 



proceed always in straight lines 233 



Vessels, their modification so unessential as all oc- 



casionally to occur in different parts of the same tube 233 

 Vegetable structure, the general components of . . 224 

 — — its solids, supposed to be composed 



simply of the membranous and cellular textures 240 

 these solids are — The membranous tex- 



ture ....... 224 



• The cellular texture — the cells analo- 



gous to those of a honey-comb in figure — situated 

 immediately under the cuticle . . . 225 



The seat of color in the young bark 



and leaf — they form the pith — enter largely into the 

 texture of petals, &c. and also make part of succulent 

 roots and pulpy fruits .... 226 



