SCIENCE AND PRACTICE OF DAIRYING. 



of capillary vessels. The practical importance of this is that the amount 

 and quality of the milk secretion principally depends on the number of 

 gland-lobules present in the udder, and the number 

 and course of the vesicles distributing the blood- 

 stream through the milk-organ. The difference in 

 the milking qualities of different cows is primarily due, 

 therefore, to the inherited individual characteristics. 



-e 



3. Formation of Milk. We conclude that, 

 since none of the organic constituents, present 



Fig. 12. Plaster of Paris 

 Cast of the Canal traversing 

 the Teat and Nipple. Na- 

 tural size. 



a, Basis of teat; d, lower 

 end of milk-cistern, and 

 upper end of nipple; e, 

 small gland-ducts ; ', di- 

 latations of the canal of 

 the teat; /, rosette on 

 the lower end of canal of 

 the teat; g, lower end of 

 outlet tube of milk-gland. 

 (Fiirstenberg.) 



in milk, is present in the 

 blood, they are all formed 

 in the gland-lobules from 

 the circulating fluids, 

 the blood and the lymph, 

 found in the udder. But 

 the changes which take 

 place in this operation 

 are little understood. 

 Before entering into a 



description of them, so far as they are at present known, it should 

 be pointed out that the milk-glands are not equally active during 



Fig. 13. Section of Membrane of Lower and Narrow portion 

 of the Canal of the Teat (x 85.) (FUrstenberg.) 



I, Epidermis; e, superficial layers of epidermis; d, sebaceous 

 gland; /,/, section of bundle of muscle-fibres. 



