30 THE SEED AND LIGHT. 



stance for its support, continues to animate the plant ; while the re- 

 mainder of the seed has thereby become subject to the inorganic laws 

 and rots, or is decomposed in the ground. The plant lives and flour- 

 ishes, and by the force of its vital powers, thus obtained, appropriates 

 inorganic matter to its support and the development of its organs, 

 until by violence or the exhaustion of its vital energies at maturity, 

 it is at length, and in turn, subjected to the force of the inorganic 

 laws it dies and is decomposed, either in the ground or by being 

 consumed by animals. The seed originally derived its vital principle 

 from its parent plant through its pericarp, or fruit, and retained it 

 within its envelops until buried and excited to germination by the 

 heat and moisture within the earth, when it gave it to its offspring. 



During the period from the birth to the death of a plant, periods of 

 repose intervene, as with biennial and perenial plants in winter. It 

 loses its leaves, the principal means of its support, and remains par- 

 tially dormant, until awakened to action by the heat of returning 

 spring, when its leaves are renewed and its dormant energies call 

 forth new shoots, buds and blossoms, and the scene of life, health, vi- 

 gor and action is reenacted. 



Light is evidently one of the necessaries of life" and plays an im- 

 portant part in vegetation and the economy of plants. By it they 

 form their combustible parts. The carbon they receive must be, in 

 some way, modified by its influence before it can become a constituent 

 of the plant. During the night they probably do little more than to 

 digest the food they have received during the day and to separate and 

 give off that which is not found nutritious. Light is a primary agent 

 from the time the plant emerges from the soil to its death. Its nature 

 becomes changed by its absence so that the observer would scarcely 

 recognize its identity by its form, color, taste or odor. If a branch of 

 any spreading plant penetrates in its growth a subterranean place its 

 character becomes not only thus changed, but is found composed 

 almost entirely of water and assumes the nature of a fungus, so that 

 all of its native beauties and virtues are lost; it is a mere pulp 

 deprived of its resinous qualities. The acid taste of some vege- 

 tables as the endive and celery, may, however, be corrected by 

 bleaching. 



Diseases of Plants. 



These arise from many causes, as with man and lower animals. 

 They may be detected and cured by a careful observance of the nature 

 and wants of plants. The change in the color of the leaves of the 

 box and holly is said to be a disease or disordered condition of the 

 juices. Too great or too little food, or that which is poisonous, pro- 

 duces diseases. Too little or too great light, heat, air, water and soil ; 



