4 BULLETIN 65o, U. S. DEPARTMENT OF AGRICULTURE. 



plant of the soil foods with air and water. Garner, Allard, and 

 Foubert ' have shown that climatic conditions exert a marked 

 influence upon the oil content of certain seeds. Provided the content 

 of oil is affected by environmental conditions it is very probable 

 that the composition or the proportion of the component parts of 

 the oils is likewise modified and altered. 



Pigulevskii 2 has found from an examination of numerous plants 

 in respect to oil content and composition that the nature of the oil 

 in a plant is influenced by climatic conditions and possibly also by 

 conditions of nutrition. A large number of plants of the same 

 family grown in different parts of Russia yielded oils the nature of 

 which varied with climatic conditions. 



The effect of such climatic conditions as latitude, temperature, 

 sunshine, and rainfall have been studied by Wiley 3 and found to 

 influence the sugar content of sugar beets strongly. Likewise, 

 the starch and protein content of the wheat grain have been found 

 to be influenced by season and climate. 



Various localities will be found to have varying conditions of 

 climate and soil, the extremes and means of which act in either 

 facilitating or retarding the growth of the plants and therefore affect 

 favorably or unfavorably the formation of oil in the seeds. 



PLAN OF COMPARISON OF THE OILS. 



"The present investigation " was undertaken in order to compare 

 the oils from the various flax samples grown at the several stations 

 during the two successive seasons. The comparison in question 

 should determine tentatively those varieties producing seeds with 

 the highest yield of oil as well as oil of the best quality. Informa- 

 tion of such character is of the utmost importance in connection 

 with the production and improvement of this staple crop. How- 

 ever, it is not only important to ascertain the high oil-yielding 

 varieties of seeds, but the properties and general behavior of the 

 oils are of equal importance. The physical and chemical properties 

 of the oils determine their value to a large extent. In order to 

 facilitate the best comparison, only those properties which admit of 

 accurate measurement and which have a direct bearing upon the 

 quality of the oils were considered. 



Color, specific gravity, and index of refraction are important 

 ph}*sical properties in which variations can easily be detected. 

 Since the color of most drying oils is an important consideration, 

 but does not admit of measurement, it was necessary to describe 



1 earner, W. W., Allard, H. A., and Foubert, C L. Oil content of seeds as affected by the nutrition of 

 the plant. In Journ. of Agr. Res., U. S. Dept. Agr., v. 3, p. 2-18. 1914. 



2 Pigulevskii, C V. In Zhurn. Russk. Fiz.-Khim. Obshch., v. 47, p. 393-405, 1915; v. 48, p. 324-341, 1916. 

 ' Wiley, H. W. Influence of environment on composition of plants. In Yearbook, Dept. of Agr., 



for 1901, p. 307, 310. 



