8 



tie sacks lined on the inside with cells, which are the true points where 

 milk is formed. The fat globules, says Foster, can be seen to form 

 in these lining cells, and are forced out into the cavit}- of the little 

 sacks. It is believed that the constituents of the milk, namely : the 

 fat, caseine and sugar are made within these cells, and out of the cell 

 contents, not out of blood at all. The blood brings digested food to 

 the udder, it there nourishes and furnishes material from which to 

 grow these lining cells, and the cells, as a peculiarity of their own, 

 have the power of changing the protoplasm which they contain into 

 milk. The blood that goes to the udder is not different from the 

 blood that goes to sustain and nourish the other parts of the body, and 

 food which is capable of producing a good growth of muscle or bone, 

 or of fattening an animal, or in sheep, of producing a good growth 

 of wool, will, if fed to a cow during her milking period, produce growth 

 in the lining cells of the udder and these will see to it that milk is 

 forthcoming. This theory of milk production is certainly no more 

 difficult to accept than the well known fact that a grafted or budded 

 tree may have two branches originating at the same point, one pro- 

 ducing sour fruit, the other sweet, and yet both are nourished b} 7 the 

 same sap taken up by the same roots, and necessaril}- containing the 

 same plant food. The explanation, so far as we are able to give one, 

 is that the character of the cells of which the two grafts are made 

 up and of the fruit after it sets is such that one develops a fruit 

 thai is acid, while the other develops a fruit in which the sugar taste 

 predominates. Now, it can not be said that it is the sap, or the food 

 of the tree, but it is a power within the living cells of the plant itself. 



The whole of this may be condensed into the following : We feed 

 to supply the blood with substances capable of promoting a rapid 

 growth of the cells which line the udder, and their nourishment is 

 not essentially different from that of any other tissue of the body. 



If this is a true and logical conclusion, then it is probable that the 

 notion that one ration is a " butter ration," another a " milk ration," 

 a third a "cheese ration,'' etc.. is largely a delusion, and it is prob- 

 ably true that food which is sufficient in quantity and so proportioned 

 in its parts that it nourishes the body well, will produce normal milk, 

 the quality of which will be chiefly determined by the characteristics 

 of the cow to which it is fed. 



FOOD. 



" We may now ask what food is, and in answer may say that food 

 is any substance which can be digested by an animal and which may 

 contribute to the growth and nourishment of the body. 



All food is made up of parts of unlike chemical composition ; 

 starch, sugar, oil, fiber and albuminoids are found in varying propor- 

 tions in our feeding stuffs. 



For the purposes of the stock feeder we may put all of the constit- 

 uents of the various fodders we use into two classes, albuminoids and 

 non-alhu m 'molds. The former arc a class of substances which con- 



