THE DIFFERENT KINDS OF STEM. 31 



winter, it will become a biennial. On the other hand, tropical 

 perennial plants, ^when transported into temperate climates 

 become annuals. For example; The beautiful climbing vine 

 so much cultivated called (Cobaea scandens,) and which endures 

 but for a year in these latitudes, is a perennial in Chili and 

 Peru its native country ; so also the castor oil plant, (Ricinus 

 communis), which in Africa forms an elevated tree, is an 

 annual with us. 



In the more highly developed plants, such' as shrubs and 

 forest trees, the act of flov ering and fruiting consumes only the 

 nutriment enclosed in the peduncle and its immediate supports, 

 but the rest of the plant is not injured. Yonder leafless tree, 

 whose branches wave in the winter's wind, loaded with snow, 

 is still fraught with life. All along its central axis, in its 

 branches, and innumerable branchlets life exists, dormant 

 beneath the scales of its numerous buds. The last vegetative 

 process of plants with ligneous and persistent stems, in autumn, 

 is, in fact, the formation of the bud, wherein life lies dormant, 

 yet protected from the severest cold of winter until spring 

 awakens it to a new existence. The following year these buds 

 or phytons (^rov, a plant,) as they have been correctly namecl, 

 develope on the stem or axophyte, and from them ligneous 

 matter descends, which gives an additional enlargement and 

 strength to the vegetable axis. In forest trees, therefore, the 

 stem acquires its greatest development. A forest tree, philoso- 

 phically considered, is not an individual plant, as is commonly 

 supposed, but a community of individual plants growing 

 together about a common vegetable axis. These phytons have 

 a downward as well as an upward development, and the stem 

 or axophyte is formed by the commingling of the ligneous or 

 fibrous matter which descends from them, and which spreads 



