A FIRST REPORT ON THE RELATIONS BETWEEN 

 CLIMATES AND CROPS. 



PART I.-LABORATORY WORK, PHYSIOLOGICAL AND EXPERI- 

 MENTAL. 



Chapter I. 



GENERAL REMARKS. 



It is not possible to conceive of an intelligent solution of the com- 

 plex problems offered by plant life in the ojjen air and cultivated 

 fields without first considering the innumerable experiments that 

 have been made by experimental botanists. It is therefore necessary 

 for the student and the practical man alike to know something of the 

 laws of growth, as presented in the elaborate treatises by Sachs, Vines, 

 Goodale, and others. I will at i3resent simply collate those special 

 results that bear upon crojjs as the final object of agriculture and 

 confine myself very closely to the relation between the crop and the 

 climate, in order to avoid being drawn into the discussion of innumer- 

 able interesting matters which, although they may affect the crop, 

 yet are understood to be outside the province of climatology. By 

 this latter term I understand essentially the influence on the plant of 

 its inclosure, i. e., the sky or sunshine, soil, temperature, rainfall, and 

 the chemical constitution of the air, either directly or through the 

 soil. 



THE VITAL PRINCIPLE— CELLULAR AND CHEMICAL STRUCTURE. 



The growth of a plant and the ripening of the fruit is accomplished 

 by a series of molecular changes, in which the atmosphere, the water, 

 and the soil, but especially the sun, play important parts. In this 

 irocess a vital principle is figuratively said to exist within the seed or 

 •lant and to guide the action of the energy from the sun, coercing 

 he atoms of the soil, the water, and the air into such new chemical 

 ombinations as will build up the leaf, the woody fiber, the starch, 

 he pollen, the flower, tlie fruit and the seed. 



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