PRINCIPLES OF VETERINARY SURGERY 



545 



found a melanotic tumor two centimeters in diameter in the 

 left temporal lobe, and Nibbert one the size of a pea in the 

 right cerebral hemisphere, and another as large as a goose 

 egg in the orbital fossa. In the brain they have been found 

 in the pituitary gland, the optic commissure, the lateral 

 ventricles, and Bouley refers to one that started from the 

 right petrous temporal and penetrated through the supra- 

 sphenoidal duct, englobing the seventh and fifth nerves. 

 Blanc reports an analogous case. 



The Skin. — The skin, associated with the epidermis and 

 its glands, presents more complicated lesions.- According 

 to an unpublished publication of Blanc, the melanotic infil- 



FiG. 65. 

 Melanosis of the Lumbar Region of the Horse. M. 

 D. M. Melanotic Deposit. V. Vertebrae. S. 



Spinal Cord. 

 Sacrum. 



tration begins in the epithelial cells of the sudoriferous 

 glands, which become tumefied as the result of a reaction 

 of the periglandular connective tissue, which in turn be- 

 comes pigmented, and thus forms a nodule of one milli- 

 meter at the maximum. In the course of time the nodule 

 swells through the periphery while its central cells, — sud- 

 oriferous glands, — die, and resolve into a mass of granules. 

 The process occurs simultaneously at different points, 

 which often results in very remarkable accumulations 

 in the perineum of the horse. In cutaneous melanosis the 

 skin is thickened, slate-colored, filled with black blotches, 

 tumefied and riddled with black nodules that raise the epi- 



