00 THE PLANT IS A FACTOUY. 



The Plant Is a Factory.—" All tlio labour of Ww ].liiiit by 

 wliich out of iiir, wator, and a pinch of divers salts scattorod in 

 the soil, it builds up loaf and iL^eni and roots, and puts toj^'otlier 

 material for seed or bud or bulb, is wrou},dit aud wroujjbt only 

 by the {^reen cells, which i^ive greenness to leaf and jjranch or 

 stem. We nuiy say of the jjlant, that the green cells of the 

 green leaves are the blood thereof. As the food wliich an aninud 

 takes remains a mere burden nntil it is transmuted into blood, so 

 the material which the roots bring to the plant is mere dead food 

 till the cunning toil of a chlorophyll-holding cell has passed 

 into it the quickening sunbeam. Takeaway from a i)lant even 

 so much as a single green leaf, and you rob it of so much of its 

 very life blood." (Masfcrf^, quoted from (fdrdr tier's f'liroiuch'). 



A living plant is a machine or a factory, which, uiuler the in- 

 fluence of light and lieat, transforms raw materiids into organic 

 matter, suitable for enlarging the plant or enabling it to grow. 

 In nearly all cases, some portions of a i)lant are dying while 

 others are growing, and to some extent, one part is independent 

 of other portions. This enables a plant to change its place of 

 growth, to feed on its own stock of nourishment, or to recuper- 

 ate when injured. The formation and enlargement of now cells 

 constitute growth. To be ready for absorption by plants, matter 

 must be in a liquid or gaseous condition. To a great extent a 

 plant takes what it likes best, or is capable of controlling the 

 quantity of any substance absorbed. 



Of the materials assimilated, a part goes at once to form cell 

 walls, cork, mucilage, etc., and can never be changed by the 

 plant into matter for constructing other parts of the i)lant, while 

 other portions of assimilated material take the form of starch, 

 oil, inulin, and are likely to be again changed and transferred 

 once or more times to other portions of the plant. 



Only a very small part of the most fertile soil is in condition 

 to be used for plant food. Some soils may contain a large 



