SECT. XIIT. GR ASSES. 387 



of wind. As no solid matter can enter the roots of a 

 plant, the silex must be absorbed in a state of solu- 

 tion ; and, as it coats the surface, which is full of 

 pores, the liquid is removed by perspiration, and the 

 silex is consolidated. The whole of this family abounds 

 in sugar, and its farinaceous products are too well 

 known to require any notice. 



The grasses seem to have been the means of revealing 

 the earliest dawn of plant life, for the Hon. Sidney 

 Osborne discovered that the colourless protoplasm, or 

 organizable liquid extracted from the roots of young 

 wheat, produced spontaneously and simultaneously 

 double ovate vesicles, or cells, such as are found in the 

 roots themselves ; and in that liquid, though hermetically 

 sealed in glass tubes, the formation of these vesicles or 

 cells was as active after six months as in the liquid 

 freshly taken from the young plant. Mr. Osborne 

 believed these vesicles to be the earliest organisms of 

 plant life, and that this is the direct and prevailing mode 

 of production of the embryo. This accords with the obser- 

 vations of Messrs. Wenham and Devey. 



Many other very remarkable plants belonging to the 

 Monocotyledons might be mentioned, as the Dracaena 

 Draco, or Dragon tree of Teneriffe, one of the most an- 

 cient trees existing ; the Pandanus, or screw pine, with 

 its aerial roots, indigenous in the islands of Oceania; 

 and the Zostera, or sea wrack, the only flower-bearing 

 plant except one that inhabits the ocean ; their flowers 

 are minute and bisexual, are rarely produced, but they 

 cover large areas with long grassy leaves. Bulbous 

 plants, and the Orchidacese, the most splendid orna- 

 ments of our gardens and hothouses, are members of 

 this class. Of the former, the snowdrop, crocus, colchi- 

 cum, arum, hyacinth, narcissus, tulip, and lily form a 

 group of singular beauty. 



A bulb is merely a subterranean stem remaining per- 



c c 2 



