Neoplasms 377 



Melano-Sarcomata or Melanomata are characterized by de- 

 position of a blackish pigment, both in the cells and intercellular 

 substance. While common in the horse, they are rare in the dog. 

 They arise especially from regions where there are already pigment- 

 containing cells, notably from pigmented moles. They are ex- 

 tremely malignant, and secondary deposits are often found at con- 

 siderable distances. They have been found in the Lips and Mouth, 

 whence they have traveled to the Lungs, appearing there in the 

 form of black interlacing lines (Lafosse, Bruckmueller). This 

 condition must not be confounded with the more common one of 

 coal-dust deposits (anthracosis pulmonum). Melanoma has also 

 been seen at the Base of the Brain in the form of little nodosities 

 (Bruckmueller). According to Leblanc, mixed melanotic growths 

 are not uncommon. There is a very good specimen of melanotic 

 sarcoma of the Pectoral Mammae in the Army Medical Museum 

 at Washington. Sutton refers to a variety of melanosarcoma which 

 seem to become mainly a source of pigfment, which may enter the 

 circulation and be discharged in the urine as melanin. Such a 

 tumor was observed by Bunker. It was situated Subcutaneously 

 and discharged an offensive black matter through several openings. 

 Another tumor composed of fungoid growth mixed with melan- 

 otic matter was removed from the Breast by Crisp, and the animal 

 succumbed twelve months later to the same disease in the Lungs. 



Glio-Sarcomata. A glio-sarcoma is a tumor containing neuro- 

 glia-cells mixed with sarcomatous elements, occurring in the central 

 mass of the brain or spinal cord. With regard to gliomata and glio- 

 sarcomata a difficulty presents itself in dividing tumors according 

 to their embryology. The ordinary sarcoma is derived from or- 

 dinary mesoblastic connective tissue. The glioma which closely re- 

 sembles it in structure is derived from the neuroglia, the connec- 

 tive tissue of the brain and retina, but this connective tissue, like 

 the nerves themselves, is of epiblastic origin. A tumor of this 

 nature, situated in the neighborhood of the Gasserian Ganglion was 

 observed by Gratia. 



Endothelial Sarcoma or Cholesteatoma is a term applied to a 

 proliferation of endothelial cells aggregated into nodules of a pe- 

 culiar glistening pearl-like appearance. They originate from serous 

 membranes, lymphatics, blood vessels, and from the pleural and 

 cerebral membranes, and also occasionally in glandular organs. 



