How the Plant Grows. 13 



On August 21, at the milk stage, the glucose and sucrose together 

 amounted to nearly 800 Ibs., which is more than the total weight of 

 the starch stored at that period. After the milk stage was reached, 

 the glucose and sucrose did not increase, while there was a continu- 

 ous and rapid increase in starch, of which there was nearly a ton 

 and a half when this acre of corn was ripe. During all the periods, 

 glucose and sucrose were being steadily formed in the leaves of the 

 plants and transferred from them thru the sap to the swelling ker- 

 nels of the ear. Here these sugars were changed to insoluble starch, 

 which was compactly stored about the germs in the corn kernels. 



Adding together the glucose, sucrose, and starch and subtracting 

 this sum from the total nitrogen-free extract found at the same 

 period, as reported in the first table, there is a remainder of nearly 

 1300 Ibs. This excess must have been largely pentosans and the 

 soluble celluloses. 



As the sugars were built, a portion was changed into cellulose, 

 forming the woody framework of the plant structure the roots, 

 stems, tassels, leaves, husks, cobs, etc. A second and larger portion 

 was changed to starch and stored in the kernels. The elements of a 

 third portion must have been combined with nitrates and other 

 mineral matter taken from the soil to form the nitrogenous com- 

 pounds the amids and proteins. 



In reviewing the tables so graphically setting forth the develop- 

 ment of America's greatest agricultural plant, the reader is re- 

 minded that, in producing this acre of corn, probably not over 10 

 Ibs. of seed was placed in the ground in the spring time. From this 

 insignificant beginning, by the following October, about 120 days 

 later, the resultant plants had gathered inorganic matter carbon 

 dioxid from the air, and water, nitrogen, and mineral matter from 

 the soil and built all these, first into primary organic forms, and 

 finally into complex organic parts of their structure. The product 

 of such building amounted to over 14 tons of green or 4 tons of dry 

 matter, all largely available for nourishing the animals of the farm 

 and, thru them, man. This is a forceful illustration of Nature's 

 wonderful processes of food production occurring all about us un- 

 der the guiding mind of man. 



The reader who will thoroly familiarize himself with this study 

 of the growing corn plant can readily extend his acquirement to all 

 the other crops of the farm. Thus equipped he is in position to 

 study the composition of the bodies of farm animals and consider 

 how they are built up and maintained by food derived from plants, 

 as later presented. 



