6 



in order that the nutrient material stored up in the grain may be changed 

 and rendered soluble by the vital phenomena of growth. 



But for the plant to attain full vigour something more than water is 

 necessary. If a few seeds are sown in ordinary garden soil in a pot the same 

 mode of development may be observed, but the root is hidden underground, 

 and only the seed leaves are seen elevated into the air. Instead, however, of 

 stopping at that stage of growth as shown in the other experiment, the stem 

 will lengthen out, fresh leaves will be formed, and in due time the plant will 

 produce flowers and fruit. This shows that an essential requisite of plant 

 growth is derived from the soil, and yet the amount of mineral constituents 

 contained in the plant is relatively very small. A large portion of a young 

 growing plant is formed of water, hence the great loss of weight which is 

 observed when the plant is dried. Of what remains of the dry weight and 

 bulk the chief proportion is carbon which has been abstracted from the 

 atmosphere, and only a very minute quantity of mineral substance remains, 

 which has been taken from the earth. 



If a plant is burned in the open air the water is driven off as vapour, the 

 carbon flies away as smoke, and only a small quantity of white mineral ash 

 is left behind. But if the fire be smothered when burning fiercely, or if the 

 plant be cremated in a closed retort, the residue is a very complete and 

 perfect skeleton, composed of almost pure carbon, the water having been 

 evaporated, this is commercially known as charcoal, and it has been derived 

 from the atmosphere where there is always present a small quantity of carbon 

 di-oxide, which is derived from the breathing of animals, the combustion of 

 fires, &c. This is absorbed by the leaves and built up by the vital activity 

 of the plant into its various tissues. It is, therefore,, plain that the plant has 

 two sources of food supply — liquid and gaseous. The roots imbibe the liquid 

 nutriment in the form of water in which is dissolved various mineral salts 

 and earths, including also nitrogen which is washed down by the rains into 

 the soil, whilst the gaseous elements are continually being absorbed by the 

 leaves. The nutrition of the plant is solely performed by these two organs 

 and nothing in the laboratory of nature is more marvellous than the magical 

 power by which the dead inert inorganic elements are changed as by a wizard's 

 touch into the stately tree, the fragrant flower, and the nutritious life sustain- 

 ing fruit. 



HOW PLANTS ARE REPRODUCED. 



Man in his vanity is but too apt to conceive that he is the acme and per- 

 fection of nature's handiwork, therefore, in virtue of this position every 

 manifestation of nature's power and skill in other forms of life are subordinate 



