WORK DONE BY PLANTS 



inside the leaf. If you were to imagine a square yard of 

 leaves all taking in sunshine and making starch as they do 

 in fine weather ; then if you weighed all these leaves, and 

 then weighed them again one hour after they had been in 

 the sunshine, of course that square yard of leaf surface 

 should be heavier, because a certain amount of starch has 

 been formed in it. The amount actually made in one hour 

 has been estimated by Dr. Horace Brown as 5^^ lb. So 

 that 100 square yards of leaves working in sunshine for 

 five hours might make one pound of starch. But one can 

 estimate the activity of plants in another way. Look at the 

 amount of work done by the Grass, etc., on an acre of pasture 

 land in one year. This might entirely support a cow and 

 calf during the summer ; all the work done by these 

 animals, as well as all the work which can be done on the 

 beef which they put on, is due to the activity of the grasses 

 on that acre. Moreover it is not only these large animals 

 that are supported, but every mouse, every bird, every 

 insect, and every worm which lives on that piece of ground, 

 derives all its energy from the activity of the plants 

 thereon. 



All work which we do with our brains or muscles involves 

 the consumption of food which has been formed by plants 

 under the warm rays of the sun. 



So that man's thoughts and labour, as well as that of every 

 living creature, is in the first instance rendered possible 

 by sunshine. 



But the sunlight, besides this all-important function, 

 affects plants in other ways. 



One of the most interesting of the early spring flowers is 

 the Coltsfoot. On bare blackish and unsightly heaps of 

 shale one may see quantities of its golden blossoms. Now if 



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