550 PRINCIPLES OF VETERINARY SURGERY 



thyroid gland is affected it exhibits all the characteristics 

 of cancerous goitre, from which it can be differentiated only 

 by section. Melanosis of the eye generally affects. the menv 

 brana nietitans, carunula lachrymalis and the upper eyehd. 



Melanotic tumors of the limbs are rarer. They may 

 counterfeit side-bones. They sometimes develop under the 

 mastiodo-humeralis and present the appearance of the cold 

 abscess so common in that region.. 



They may compress the pneumogastric nerve and cause 

 tumultuous and sonorous beatings of the heart. In the 

 lymphatic glands they are often the cause of grave func- 

 tional derangements. In the subglossal gland it may be 

 mistaken for glanders (See Bissange's case page 539). 

 The glands of the groin and of the mesentery are frequently 

 attacked. The former may impede the movements of the 

 limbs, those of the lungs may reproduce all the phenomena 

 of bronchial adenopathy, etc. The nerve tissues sometimes 

 become compressed with melanotic infiltration. We have 

 reported cases of the brain, the spinal cord, the lumbo- 

 sacral plexus, etc. King found a large one in the subsacral 

 region that extended into the neural canal and compressed 

 and atrophied the spinal cord. Similar tumors are occa- 

 sionally encountered. Mawry observed a compression of 

 the radial nerve from a melanotic tumor situated in the 

 forearm. They have also been observed to envelop the cer- 

 vical ganglia of the sympathetic system and the pneumo- 

 gastric nerve. In this localization they cause paresis, 

 paralysis and paraplegia. 



Independent of digestive disorders succeeding obstruc- 

 tion and contraction of the rectum and anus, disorders of 

 deglutition may result from invasion of the retropharyn- 

 geal gland, compression of the pharynx, trachea, oesopha- 

 gus, bloodvessels and nerves. The tumors developed in 

 the abdominal cavity (peritoneum, diaphragm, intestines. 



