Det. IS. 1914 Oil Content of Seeds and Nutrition of Plant 241 



actual quantity of oil stored in the seed produced under these condi- 

 tions was somewhat greater than in those grown in the Coastal Plain 

 region. There was also considerable yearly fluctuation in the oil con- 

 tent of the seed in both sections, owing to varying seasonal conditions. 

 (See Table X.) As already noted, the uniformity in behavior of all 

 the varieties of cotton contrasts sharply with the varietal differences 

 observed in soy beans. The average difference in oil content for the 

 six varieties of cotton as grown in the two localities is greater than 

 the varietal differences in either locality. 



OIL CONTENT OF SEED AS AFFECTED BY SOIL 



In dealing with the response of the plant to differences in the environ- 

 ment, it is frequently sought to differentiate between the effects of 

 climate and those ascribed to the soil. Climate, or the average weather, 

 as ordinarily understood, refers to conditions of the atmosphere, of 

 which temperature and moisture are perhaps the most important as 

 factors of nutrition. But the soil is likewise subject to variation in 

 temperature and moisture, and there must be a tendency toward equilib- 

 rium in temperature and moisture between these two media in which 

 the plant lives. 



It is true that under any fixed weather, or climatic, conditions plants 

 grown on contrasted soil types may show well-defined differences in 

 their development, but such relationships are subject to change with 

 any change in the climatic factors. There is ample evidence to show 

 that the differences in plant development observed on contrasted soil 

 types during one season may be completely reversed in another season. 

 Again, it is true that in extreme cases differences in climate may pro- 

 duce certain definite differences in plant development more or less inde- 

 pendently of the soil type. Within ordinary ranges of soil and climatic 

 differences, however, it is hardly possible to develop far-reaching gen- 

 eralizations as to the specific effects of either independently of the other, 

 for change of climate results in a change of soil conditions, and vice versa. 



In spite of the above-mentioned limitations, which must apply in con- 

 sidering soil and climate as environmental factors, it seemed desirable 

 to obtain data as to the influence of differences in soil type on the accumu- 

 lation of oil in the seed as produced under varying seasonal conditions. 

 In the experiments with cotton six representative Upland varieties were 

 grown for three consecutive years (1909-1911) at Thompsons Mills, Ga., 

 on two adjoining but contrasted types of soil, the original lots of seed 

 being used for each year's planting. For convenience these soU types 

 are designated as "red soil" and "gray soil," respectively. Both be- 

 long to the Cecil series and were in a good state of cultivation. The red 

 soil is a comparatively heavy, tenacious clay, while the gray soil is an 

 open-textured sandy loam. As all of the varieties were affected in a 



