196 BOARD OF AGRICULTURE. 



the comparative activity of the one or the other set of organs. 

 Both these organs are subject to the breeder's influence. 

 If we breed so as to enlarge and stimulate the adipose tis- 

 sue to great activity, we produce an animal whose constitu- 

 tional predisposition is to accumulate fat. If, on the other 

 hand, we increase the activity of the mammary glands by 

 breeding and feeding with sj)ecial reference to this object, 

 we develop the size and activity of these glands, and the 

 result is an animal tliat will yield large quantities of rich 

 milk. The form, size, position, and functions of these or- 

 gans, come more properly into the department of animal 

 physiology, and we have not time to devote to them. It is 

 sufficient here to say that the mammary glands are stimu- 

 lated to special energy after the birth of the offspring ; so 

 that this activity becomes superior to the tendency to form 

 fat : and at such times, if the food is deficient in oily matter, 

 the fat already laid up in the system is again taken up into 

 the circulation, and goes into the formation of milk. 



So you see, when the mammary glands are acting in a 

 healthy and energetic manner, the fatty matters of the blood 

 which passes through them are secreted in the form of milk, 

 and, if these fatty matters are deficient, the fat already laid 

 up in the cells of the adipose tissue is dissolved, and goes on 

 in the circulation to form milk ; and if this fat gives out, and 

 is not kept up by the food, the very substance itself of the 

 adipose tissue is capable of absorption into the system, so 

 tliat ever after it will become more difficult for the animal to 

 take on fat. This explains, perhaps, the difficulty of bringing 

 up an animal that has become emaciated, what is called " hide- 

 bound." The adipose tissue — the organs whose function it 

 is to deposit fat from the blood — is gone, dried up, absorbed 

 in the system. 



Now, in some instances, the mammary glands get into an 

 unnatural and torpid state, lose their energy to such an ex- 

 tent that even the birtji of the offspring is not sufficient to 

 call them into activity and excite them to energy. In such 

 cases, even with good food, and with all the rich, fatty ele- 

 ments in the blood which courses through these glands, they 

 fail to appropriate it as milk ; and the blood will pass on to 

 carry its rich treasures to other parts of the body. 



Our object in breeding stock for the dairy, therefore, ia 



