59 



hand, we must not lose sight of the external factors of soil heterogeneity, 

 water and temperature variations and extremes, light, etc., which affect by 

 Increased or diminished nutrition the inherent tendencies of the plant. The 

 high oil and high protein corn strains, so carefully selected and maintained 

 by the Illinois Agricultural Experiment Station, show marked seasonal 

 changes, plus and minus, due to the effect of the environment at the sus- 

 ceptible period of development, modifying or conditioning the hereditary 

 determiners. This becomes all the more clear when we fully realize the 

 complicated structure and remarkable adaptive powers of the living substance. 

 The green plant is built up of innumerable cells grouped into tissues 

 and organs for the performance of specific functions. Each cell consists of a 

 bit of differentiated protoplasm, which, with Huxley, we may call the 

 "physical basis of life." It is that substance alone that through distinctive 

 functional processes nourishes itself, respires, moves and grows, adjusts 

 itself in a definite manner to stimuli from the external world and, finally, 

 maintains the uninterrupted succession of life through generation. It cannot 

 take its origin from the physical world, but is increased in quantity and 

 reproduced through properties it alone possesses. We may follow it in 

 continuity from grandparent to parent, to offspring. It carries potentially 

 the hereditary factors that a long line of descent has given it, and these 

 are activated or inhabited by the internal conditions prevailing at a given 

 stage of development or by the environment acting upon its delicately 

 organized substance. A continuous cycle of chemical and physical inter- 

 actions are constantly taking place between the living cells and the physical 

 world. Without cease certain substances carbon, hydrogen, oxygen, magne- 

 sium, nitrogen, iron, etc. totally different from its own body, enter the 

 organism and, in an endless round of cellular chemical activity lose their 

 identity. They pass through a series of chemical combinations of increasing 

 complexity, and finally may appear as part of the living substance. But 

 the organic substances produced, the protoplasm itself, are unstable. They 

 are constantly being broken down with a liberation of energy and the waste 

 products return to inorganic nature. The living substance of our growing 

 crops is in such a state of incessant change, a constant transformation and 

 transfer of energy is going on, it is in statical equilibrium only when it is 

 dead. "As no man," says Huxley, "fording a swift stream can dip his foot 

 twice into the same water, so no man can with exactness affirm of anything 

 in the sensible world that it is. As he utters the words nay, as he thinks 

 them, the predicate ceases to be applicable; the present has become the 

 past; the 'is' should be 'was.' And, the more we learn of the nature of 

 things, the more evident is it that what we call rest is only unperceived 

 activity; that seeming peace is silent but strenuous battle. In every part, at 

 every moment, the state of the cosmos is the expression of a transitory 

 adjustment of contending forces; a scene of strife, in which all the combat- 

 ants fall in turn." 



SOIL AND CLIMATE INFLUENCE. 



With an organization so delicately adjusted and so responsive to external 

 conditions, it is apparent that differences in soil and climate will molify 

 the vegetative or nutritive functions and through them decrease the yield 

 and change the nature of the progeny. 



This progeny, the seed, is in corn or wheat composed of embryo and 

 endosperm. The embryo results from the union of two cells, male and 

 female, brought together through pollination and fertilization. By this 

 union the two bits of protoplasm from different parents and, hence of dif- 

 ferent ancestral history, will determine the gemetic constitution of the 

 embryo that at once begins to form through increase in the number of cells 

 by division. Development proceeds to a definite stage and stops. The seed 

 passes through the phases of ripening and remains dormant until favorable 

 conditions for growth are given it. 



The endosperm results from the union of three cells, two of maternal 

 and one of paternal origin. The single cell thus formed divides and forms 

 the storage tissue which surrounds to greater or less degree the embryo. 

 The cells comprising the endosperm are filled with sugar, oil, starch, proteins, 



