MILKING AND MILKING API»ARATUS. 215 



affects the yield of milk considerably. It has been shown 

 that the milk is produced by a breaking down and de- 

 composition of the cells of the glandular tissue, which 

 are in a condition of engorgement by reason of the 

 excited circulation of blood, and the formation of tissue 

 for this large accession of blood through the arteries 

 and capillary vessels. Whatever will tend to excite this 

 activity of the glandular substance will necessarily in- 

 crease the flow of milk. The rapid pressure, gently and 

 pleasantly performed upon the udder in the act of milking, 

 and the continuous pulsations following each movement 

 of the hands, tend to excite the circulation in the udder 

 and increase the formation of cells wdth the fat granules 

 contained in them, and as these must necessarily break 

 down as fast as they are formed, to prevent tumefaction 

 of the glands, the production of milk is the most rapid 

 at this time and during the act of milking. There can 

 be little doubt that the milk is thus made very rapidly 

 while the milking is going on, and the more rapidly the 

 milking is performed the more the glands are excited to 

 action and the consequent secretion of milk is effected. 

 In fact, a cow which yields from twenty-four to forty- 

 pounds of milk, as some do, at one milking, must neces- 

 sarily secrete a large portion of this during the process of 

 milking. The '^giving down" of the milk, as the pop- 

 ular expression has it, is a physiological and actual fact, 

 and if so the converse of it, the *' holding up of the 

 milk," must be equally a fact. 



Hence the milking must be performed in the most 

 effective and gentle manner; in such a way as to avoid 

 nervous resistance on the part of the cow and secure 

 the necessary excitation of the udder. When the milker 

 seizes upon the lower part of the teat and simply presses 

 the milk out of this, without exerting any pressure upon 

 the milk reservoir, showai in the engraving (figure 25) in 

 Chapter XV., the milking must be much slower and the 



