520 



GENITAL ORGANS OF THE COW 



somewhat ellipsoidal in form, l)ut flattened transversely. The base (or dorsal 

 surface) of each gland is slightly concave and slopes obliquely downward and for- 

 ward in adaptation to the abdominal wall, to which it is adherent; posteriorly it 

 is in relation to the large supramammary Ij^mph glands and a quantity of fat. 

 The inner surface is flat, and is separated from the other gland by a well-developed 

 double septum. The outer surface is convex. Four well-developed teats are 

 present; they average about three inches (ca. 7 to 8 cm.) in length. It is customary 



Fig. 4lCi. — CROSs-SECTiON of Mammary Gi.ands of Cow. 

 a, Body of gland; b, lactiferous siiui.s; r, cavity of teat; d, duct of teat; c, intermammary groove; /.septum 



between gland.-?; g, supramammary fat. 



to consider the udder to consist of four "quarters." There is no septum nor visible 

 division between the two quarters of the same side, but, on the other hand, in- 

 jections of fluids of different colors into the two teats of the gland demonstrate that 

 the cavities drained by them do not communicate. 



The size and form of the glands vary greatly; in the highly specialized dairy breeds (e. g., 

 Holsteins) they often attain enormous dimensions. The size of the udder is not a certain index 

 of its productivity, since some so-called "fleshy" udders contain a very large amount of inter- 

 stitial tissue and relatively little parenchyma. Small accessory teats often occur posteriorly; 

 commonly these are rudimentary and imperforate (polythelia), but sometimes they drain a small 

 amount of gland substance (polymastia). Sanson described a case in which there were sevea 

 teats, all giving milk. 



