PRINCIPLES OF VETERINARY SURGERY 539 



a hazelnut. The generalized form is often accompanied by 

 abundant infiltration of the connective tissue of the perito- 

 neum, in which are found enormous black masses involving 

 the mesentery and the intestinal w^alls. (Fig. 60). 



The melanic pigment may infiltrate the bones, even those 

 of the head, especially the temporal. It invades the osseous 

 medulla and thus provokes fractures of such bones as the 

 pelvic arch, the dorsal vertebrse and the ribs. Nibbert has 

 observed cystic-melano-sarcomata develop originally on the 

 ribs. • 



2. The Muscles. — Black tumors have frequently been 

 found in the different muscles under the shoulder ; in the 

 rhomboideus and upon its surface; in front of the shoulder, 

 under the mastoido-humeralis ; in the longissimus dorsi ; un- 

 der the tensor fascia latse; in the region of the scapulo- 

 humeral and coxo-femoral articulations ; near the pterygoids, 

 etc. The diaphragm is not always spared. It may be invaded 

 with oval, flattened tumors that simulate the cotyledons of 

 the uterus of large ruminants, or pigmentary infiltration sim- 

 ilar to that of the peritoneum. 



3. Cartilage. — The lateral cartilages, the scutiform car- 

 tilage, the membrana nictitans and the caruncula lachry- 

 malis are the cartilaginous structures occasionally affected. 



The eyes, atrophied fromi periodic ophthalmia, are some- 

 times invaded with pigm>entary deposits that replace the 

 vitreous humor. 



4. Lrjmiphatic Glands. — When lymphatic glands are en- 

 croached upon by pigment they become hypertrophied, hard 

 and fibrous, and on section exhibit the characters already 

 described. Bissauge observed melanosis of the sub-glossal 

 gland, simulating the tumefied gland of glanders. It pre- 

 sented the form of a hard, lumpy, adherent, and insensitive 

 body the size of a walnut. The nostrils discharged a sus- 

 picious mucus that gave negative results when inoculated 



