GROWTH OF PLANTS. 49 



The small turnip, grown at Tel tow,* when placed 

 in a soil which yields as much nourishment as it 

 can take up, increases to several pounds in weight. 



The size of a plant is proportional to the surface 

 of the organs which are destined to convey food to 

 it. A plant gains another mouth and stomach 

 with every new fibre of root, and every new leaf. 



The power which roots possess of taking up 

 nourishment does not cease as long as nutriment 

 is present. When the food of a plant is in greater 

 quantity than its organs require for their own per- 

 fect development, the superfluous nutriment is not 

 returned to the soil, but is employed in the forma- 

 tion of new organs. At the side of a cell, already 

 formed, another cell arises ; at the side of a twig 

 and leaf, a new twig and a new leaf are developed. 

 These new parts could not have been formed had 

 there not been an excess of nourishment. The 

 sugar and mucilage produced in the seeds, form 

 the nutriment of the young plants, and disappear 

 during the development of the buds, green sprouts, 

 and leaves. 



The power of absorbing nutriment from the 

 atmosphere, with which the leaves of plants are 

 endowed, being proportionate to the extent of their 

 surface, every increase in the size and number of 

 these parts is necessarily attended with an increase 



* Teltow is a village near Berlin, where small turnips are cultivated 

 in a sandy soil ; they are much esteemed, and weigh rarely above one 

 ounce. 



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