532 GENERAL ANATOMY. 



This morbid tissue presents a considerable diversity of ap- 

 pearance, both in the state of crudity and in that of softening. 

 Bayle enumerates from five to six species of cancers. Several 

 species of the sarcoma of Abernethy belong to this kind of 

 tissue. 



Schirrus softens sometimes partially, and then it presents 

 the appearance of cicatrices (Nicod.). In a case of this kind, 

 which I have seen recently, it seemed to me what appeared 

 to be cicatrices was the skin remaining sound in small spots 

 in the midst of a very great number of superficial and irregu- 

 lar ulcerations. 



Schirrus has been observed in most parts of the body, in 

 almost all the organs and tissues. 



IV. OF MELANOSIS. 



840. Melanosis,* cancer m&lane of Alibert is a morbid 

 tissue characterized by its black colour, which, noticed at first 

 by some observers, both in man and animals, has been speci- 

 fied and named, some years ago by Laennec. 



This substance exists under the form of isolated masses, 

 denuded or enveloped, under that of infiltration, and of platft 

 at the surface of membranes. 



The masses of melanosis vary, as to size, from the most mi* 

 nute to that of a nut: they exist in a greater or less number 

 in the same individual; they are sometimes tolerably regular, 

 sometimes mamillary, lobulated, sometimes as if formed of 

 laminae twisted or winding. These parts are united together 

 and the masses surrounded by cellular tissue. The vessels 

 surround this tissue, but do not penetrate into the black sub- 

 stance. This substance is black or brown, opaque, inodorous, 

 tasteless, firm, tenacious, and apparently homogeneous; but if 

 it be broken by percussion, and washed with water, the water 

 becomes coloured with brown or black; the tissue loses its 

 colour and remains grayish. 



Melanosis occurs in plates at the surface of the mucous or 



* Breschet, Considerations sur une alteration organiijue appeh'e degtnt- 

 rescence noire, etc. Paris, 1821. 



