MILK PRODUCTION 



463 



milk glands there is more or less connection through these 

 milk ducts between the several lobes, but none between the 

 two glands on either side of the body. 

 The milk gland, therefore, consists 

 of a framework of connective tissue 

 carrying more or less fat, of alveoli, 

 milk ducts, veins, arteries, lymph vessels 

 and nerves, the whole forming a reddish 

 gray spongy mass. In the cow the -y 

 two glands constituting the udder are 

 separated by a band of fibrous tissue 

 which serves to support the organ. 

 The udder may vary widely in the 

 proportion of connective and fatty 

 tissue on the one hand and of true 



, . ,. N , FIG. 41. Alveoli of milk 



secreting tissue (alveoli) on the other. gland . (wikkens, Form und 



A large proportion of the former gives Leben der Landwirthschaft- 



what is commonly known as a fleshy Uchen Hausthiere -) 

 udder. The size of the udder, therefore, is not the sole criterion 



of its capacity as a milk pro- 

 ducing organ. 



At the branches of the milk 

 ducts are located sphincter 

 muscles which are more or less 

 under the control of the animal 

 and the contraction of which 

 interferes with the flow of 

 milk, enabling the animal, as 

 the phrase goes, to " hold up " 

 her milk. 



549. Development of milk 

 glands. In the young animal, 

 the milk glands are rudimen- 

 tary and in the male remain so 

 during life, except in extraor- 

 dinary cases. In the female, 

 however, as sexual maturity 

 approaches, a considerable 

 formation of glandular tissue 



wirthschaftlichen Hausthiere.) takes place, but the glands 



