Acquired Characters and Effects of Nutrition. 133 



dividual variations is based, we seldom find them clearly 

 stated. And when we can, they usually consist in some 

 misapprehension of the meaning of the term Heredity. 

 Nutritional modifications are deviations of considerable 

 magnitude, which are soon lost in succeeding generations 

 in accordance with the law of regression. They do in- 

 deed bear a certain resemblance to spontaneous varia- 

 tions or sports which are of course inherited. It is per- 

 haps on some such train of thought as this that the view 

 that they are not inherited may rest. 



Ordinarv variation evidentlv must be due to some 

 cause and this must be sought for, in the last instance, 

 in the environment : that is in nutrition, using that term 

 in its widest signification. 



My experiments lead me to the conclusion that nutri- 

 tional modifications and ordinarv variations are one and 

 the same thing. Great changes in nutrition result in 

 great changes in the plant followed by a proportionately 

 speedy regression. And as the change in the organism 

 does not become independent of nutrition, a change in 

 the amount of manure in the next generation w^ill affect 

 the plant accordingly. 



Nutrition in the widest sense — the conditions of life 

 one might almost say — is at the bottom of all individual 

 variability.^ Every character varies only in a plus or luiiius 

 direction. Favorable conditions are responsible for the 

 former, unfavorable ones for the latter. Which partic- 

 ular influences are favorable and which are not, is of 

 no importance; in the words of Knight: "Superfluity 

 of nutriment is the most important cause of variabihty: 

 the kind of nutriment does not matter," he said. Future 



^ L'Unitc dans la variation; Revue de TUniversite de Bruxelles, 

 III, 1898. 



