no Human Physiology. 



oxygen, hydrogen, nitrogen, lime, silica, potash, soda, iron, &c 

 Vast numbers of animals, it is true, live upon other animals, 

 but the food of these is vegetables. The tiger eats the ante- 

 lope, the antelope eats grass. 



Plants differ from animals, excepting some of the lowest 

 forms of animal life, in the fact that they are generally a con- 

 geries of individuals. Each leaf bud has its own life, draws its 

 sustenance through" special tubes, has its own organs of 

 nutrition, is capable of an independent existence, and of 

 producing other individuals of its own kind. Thus, a single 

 bud of a plant may be cut away, grafted into another stock, or 

 made to throw down roots, and live its separate life. There 

 are animals which can be divided so that each part becomes 

 an animal, and some that live in clusters, like a bunch of 

 grapes, with a common circulation, and others that multiply by 

 division, or by producing buds which are thrown off and 

 become individuals; but these are low forms of life on the 

 confines of the vegetable and animal kingdoms. 



There are plants, and reproductive portions of plants, which 

 are provided with organs of locomotion, by means of which 

 they move about with great rapidity, and are sometimes mis- 

 taken for animals. Even starch globules have a kind of 

 quasi-spontaneous motion in their parent cells, acting under 

 the microscope as if gifted with animal life and voluntary 

 motion. 



Spore, bud, seed, whatever begins the growth of a plant, 

 must have life a living germ. This may be preserved for 

 thousands of years as in the mummy wheat, or longer, perhaps^ 

 in seeds thrown up with sand from the bottoms of deep wells. 

 Seeds are scattered everywhere by birds, by winds, by waters, 

 flying with downy feathers, often so small as to be invisible, 

 The atmosphere is full of invisible germs of vegetable and 

 animal life. 



Plants perform many acts which have the appearance oi 



