3 Anatomy, Pathology and Histology of the Mammary Gland. 



forms of the disease may be present in combination in the same 

 udder. During the tuberculous invasion nodular indurations of 

 the tissue develop, which hypertrophy and become tense, hard and 

 knotty. The lymph glands usually manifest hard, painless, thick- 

 ening, and nodular formations. Caverns may also develop in tu- 

 berculosis of the udder. 



Actinomycosis which commonly develops from the penetration 

 of actinomycotic barley beards, or particles of straw into the 

 tissue, or more rarely by embolic infection, may also be produced 

 experimentally by the injection of solutions containing actin- 

 omyces through the milk ducts. Actinomycosis of the udder has 

 been observed in cows by Peterson, Rasmussen, Bang, Harms, and 

 Jensen. Nodular formations, connective tissue proliferations and 

 softening of the tissues, localized or in larger areas, are also ob- 

 served in this disease. 



Botryomycosis and glanders enter into consideration only so 

 far as the udders of mares are concerned. 



For completeness, various growths may also be mentioned as anomalies of the 

 udder, such as fibroma, adenoma, adenofibroma, adenocareinoma, chondrofibroma, chon- 

 droma, lipoma, sarcoma, angioma, etc., which are dependent on the tissue elements and 

 the character of the tissues of which they are composed. Cystic formations have also 

 been observed. 



Not infrequently the connective tissue and the subcutis of the udder of cows may 

 show bone formations in the form of bony hooks and plates, (ossificatio plana or 

 racemosa). Parasites have also been found in the udders of cows, namely echinococci 

 (Behmert and Steuding). For further information see Kitt, Pathol. Anatomy, 1910, 

 Vol. 1, page 280. 



The author once concluded that a goat affected with adenoma papilliferum uberis 

 was troubled with mastitis, basing this decision upon an examination of the milk, although 

 the secretion contained no specific inflammatory agents. The continually increasing 

 quantity of milk was remarkable. Postmortem and histological examination finally 

 revealed the adenoma in the udder. 



Structure of the Tissue 



The external skin of the teats possesses neither hair nor 

 sebaceous or sweat glands, and continues as cutaneous mucous 

 membrane into the milk ducts, which it lines up to the cistern. The 

 mucous membrane has no glands, possesses fine folds running 

 lengthwise, and is covered by pavement epithelium which is 

 supported upon a well developed papillary base, and is firm and 

 horny next to the lumen. The papillae are extraordinarily long: 

 they apparently branch near the base, and slant towards the 

 orifice of the teats. This cutaneous mucous membrane of the 

 milk ducts continues without demarcation, with the mucous mem- 

 brane of the milk cistern, which is covered by several layers of 

 cylindrical epithelium, and possesses accessory glands which are 

 lodged in the connective tissue. The wall of the teats contains 

 bundles of involuntary muscles running lengthwise and crosswise, 

 forming a strong and elastic encasement around the canal of the 

 teats. 



The supporting structure is penetrated by numerous blood 



