YIELD OF QUARTERS ON SAME SIDE OF UDDER. 135 
THE MILK YIELD OF QUARTERS ON SAME SIDE 
OF UDDER. 
REPORTHD BY C.41,. BEACH, 
The udder of the cow consists of two glands, one on each 
side of the middle line of the body. Each gland consists of 
two lobes or quarters, each having a teat upon the lower side. | 
The end of the teat is guarded by an involuntary sphincter 
muscle. Above the teat is the milk cistern, the capacity of 
which is about half a pint. Small canals, or milk ducts, ex- 
tend from the cistern to all portions of the udder. These ducts 
divide and subdivide, gradually growing smaller as they extend 
upward. At the end of the ducts are small sac-like bodies 
called acini or ultimate follicles, which are lined with epithe- 
lial cells, in which the milk is secreted. The follicles are 
surrounded with veins, arteries, nerves, and lymphatics, and 
besides these essentials the udder may contain fatty or fleshy 
tissue. Fibrous connective tissue extends throughout the 
udder, and connects it with the body. 
The glands and quarters.are independent.—The glands on 
either side of the udder are independent of each other. It is 
stated by various writers that there is more or less connection 
between the quarters on the same side of the udder, which ren- 
ders it possible to draw from the hind teat a part of the milk 
secreted in the front quarter, and vice versa. From a physio- 
logical point of view it is difficult to understand this view of 
the matter. Dr. Babcock* reports the amount of milk yielded 
by a cow when milked one teat at a time for four successive 
milkings. At each milking the teats were milked in different 
order. Prof. Plumbt reports the yield of four cows when 
milked in the same manner. If A designate the right fore 
teat, B the right hind teat, C the left hind teat, and D the left 
fore teat, then the tables below show the effect of milking one 
*Report of Wisconsin Experiment Station, 1889. 
f¢Indiana Bulletin, No. 62. 

