366 PROGRESS OF VEGETABLE GROWTH. 



fronds-, eventually, wave in loveliness to the passing 

 winds. 



Vegetable forms of a higher and a, higher order 

 gradually succeed each other, each series perishing in 

 due season, and giving to the soil additional elements 

 for the growth of plants of their own species or those of 

 others. Flowering herbs find a. genial home on the 

 once bare rock; and the- primrose pale, the purple fox- 

 glove, or the gaudy poppy, open, their flowers to the joy 

 of light. The shrub, with, its hardy roots interlaced 

 through the soil, and binding the very stones^ grows 

 rich in its bright greenery. Eventually-the tree springs 

 from the soil, and where once the tempest beat on the 

 bare cold rock, is now the lordly and branching monarch 

 of the forest, with its thousand leaves, affording shelter 

 from the storm for bird and beast. 



Such are the conditions which prevail throughout 

 nature in the progress of vegetable growth; the green 

 matter gathering on a pond, the mildew accumulating 

 on a shaded wall, being the commencement of a process 

 which is to end in the development of the giant trees of 

 the forest, and the beautifully tinted flower of nature's 

 most chosen spot. 



We must now consider closely the phenomena con- 

 nected with the growth of an individual plant, which 

 will illustrate the operation of physical influences 

 throughout the vegetable world. The process by which 

 the embryo, secured in the seed, is developed, i$ our 

 first inquiry. 



A seed is a highly carbonized body, consisting of 

 integuments and embryo : between these, in most seeds, 

 lies a substance called the albumen, or perisperm. The 

 embryo contains the elements of the future plant the 

 cotyledons, the plumule, and the radicle; the former 

 developing into stalk and leaves, the latter into roots. 

 This embryo hides the living principle, for the develop- 

 ment of which it is necessary that the starch and gluten 



