37 2 



TRANSMISSION 



As temperature is an all-pervading influence with smaller 

 organisms, so is food an all-pervading influence with all organ- 

 isms, large or small. Without doubt it exerts a controlling effect 

 upon the quality of germinal matter produced, as it does upon 

 its quantity, and upon the maximum or minimum development 

 of the body. 



Constitutional vigor, which is the most valuable asset of any 

 plant or animal, is a heritage whose seat is in the germ from 

 which it was developed. Such a germ could be produced only! 

 by a vigorous, healthy, well-nourished parent. Anything which 

 weakens this parent constitutionally, which lowers its tone, 

 reduces its vital powers, and lowers its rate of living, must 

 of necessity affect the quality of any germinal matter it may 

 produce and the constitutional vigor of its descendants. 



We do not permit this condition to any large extent in our 

 domesticated species, plant or animal, for we realize too well 

 the consequences, but we have only to look among the underfed 

 classes and races of humans to see the evil effects of malnutri- 

 tion in weakened constitutions, low vitality, predisposition to the 

 ravages of disease, and general inefficiency wherever any great 

 functional activity, physical or mental, is required. That this 

 condition is transmitted does not admit of a reasonable doubt. 



On the other hand, races that are well nourished for many 

 generations undergo maximum development. This has been the 

 experience with all domesticated animals and plants. For the 

 most part they have been provided with all the food they needed, 

 and they have responded with a development such as never 

 came to them under natural conditions. 



Nature never produced such specimens as our modern beef 

 or milk breeds or our draft horses. Our achievement as breed- 

 ers is due, therefore, to something besides selection, and we are 

 forced to one of three conclusions : 



1. That nature never produced a perfect specimen; that is, 

 that natural conditions were never sufficiently favorable to allow 

 the individual to realize the full development to which his natural 

 endowments entitled him. 



2. That with each increment of gain through selection, estab- 

 lishing a higher general average, a new " center of variation " 



