228 CAUSES OF VARIATION 



(2) in disorders of the excretory organs ; (3) in excessive fat ; 

 (4) in sterility, especially in females, through fatty degeneration 

 of the essential sexual organs. 



Qualitative effects from the nature of the food. The color 

 of plants and flowers, and even of animals, is said often to be 

 directly influenced by their food, but it is exceedingly difficult 

 always to separate fact from tradition in this particular field, 

 because the average person has an exaggerated conception of 

 the influence of food upon the constitution of the organism, 

 often believing that a meat diet, for example, inclines to ferocity 

 and uncontrollable temper generally. Darwin l mentions the 

 practice of feeding hemp seed to bullfinches to darken their 

 color ; the fat of a certain fish to parrots, causing them to 

 "become beautifully variegated with red and yellow feathers." 

 He also states that the shells of mollusks are largely influenced 

 by the amount of lime in the water in which they grow, and 

 Beal succeeded in growing blue hydrangeas from pink stock by 

 occasional application of alum water to the roots. 



That the flavor of milk and eggs is largely dependent upon 

 food has long been known, as has the specific effect of certain 

 foods upon the texture and flavor of meat. Mumford found at 

 Illinois that the fat of pork fed upon large amounts of cotton 

 seed proved, on chemical examination, to contain a proportion 

 of true cotton-seed oil, showing that a portion at least of the 

 food had been carried over and stored unchanged in the tissues. 



That this is the exception, or perhaps more correctly the 

 lesser result, is proved by the fact that in general the identity of 

 the food is lost in the nature of the organism, showing that the 

 organism and not its food dominates results. The same meat 

 becomes dog or man indifferently, indicating that food com- 

 pounds are not as a rule carried over but rather " suffer profound 

 disruption," being reduced, if not to their elements, at least to com- 

 paratively simple compounds, the energy set free in the disrup- 

 tion being " utilized in the subsequent work of construction." 2 



The higher organisms are comparatively independent of their 

 food so far as qualitative changes are concerned. They seem 



1 Darwin, Animals and Plants, II (second edition), 269-270. 



2 Encyclopaedia Britannica, XIX (1885), article "Physiology," 21. 



