Chapter IX 



THE BREEDING AND MANAGEMENT 



OF ANIMALS 



In the foregoing chapters we have advanced a num- 

 ber of concepts and experiments relative to the action 

 of cytost in the animal body. It has been shown that, 

 depending upon its concentration, this substance may 

 exert both stimulating and toxic effects, so far as an 

 animal's health and well-being are concerned. Let 

 us now consider the application of the information 

 so far deduced to the problem of animal breeding. 



The object of the latter, whether for laboratory or 

 farm purposes, is to produce under more or less fixed 

 conditions uniformly healthy and fertile animals 

 which are as resistant as may be expected to unavoid- 

 able alterations in their environment. It is obvious 

 that in order to achieve this end as economically as 

 possible the breeding stock must likewise be kept in 

 a healthy resistant state. If the surroundings natural 

 to a given species cannot be completely duplicated the 

 breeder must devise various ways of compensating for 

 this enforced change in the animal's mode of living. 



To this end intelligent breeders have always tried, 

 in so far as possible, to duplicate climatic conditions, 

 provide exercise, and give adequate attention to 



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