34S GENERAL ANATOMY. 



divide them into two kinds. The imperfect accidental car- 

 tilages are sometimes in the state of jelly, or have the consist- 

 ence of the boiled white of egg. They have a milky, or yel- 

 lowish, or pearly-gray colour; they are partially or totally os- 

 sified, rather than becoming perfect cartilages. They are met 

 with under the form of incrustations in the arteries, and espe- 

 cially in the aorta and in the cerebral arteries; under the form 

 of cysts around morbid productions and acephalocysts; forming 

 the fistulous passages in the lungs; under the form of irregular 

 masses in goitres, and other compound tumours, and under 

 that of isolated bodies in the articulations. 



The perfect accidental cartilages are those which present the 

 character of the natural tissue, and especially its firmness. 

 Some are found forming small cysts filled with phosphate of 

 lime. Some are sometimes met with in the state of isolated 

 bodies, of a moderate volume of an obround figure, in the syno- 

 vial membranes, or at their exterior, whence they penetrate 

 into the cavity by pushing the membrane before them, enve- 

 loping itself as with the finger of a glove whose base, after be- 

 coming very thin, separates. They imperfectly ossify either 

 in part or in totality, but beginning in the centre. These car- 

 tilaginous bodies are also found in the splanchnic cavities, and 

 especially in the tunica vaginalis, into which they penetrate 

 like those just described. 



Perfect cartilages also occur under the form of incrustations 

 or plates, in the sub-serous cellular tissue of the spleen, the 

 lungs, and the pleura costalis, in the substance of the valves of 

 the heart, especially in the left side, in the sub-serous tissue of 

 the diaphragmatic pleura and peritoneum, and in that of the 

 liver in hernise, and seldom in the anterior parietes of the ab- 

 domen. All these incrustations have a great tendency to ossify. 

 Cartilages also happen in shapeless masses in the compound 

 tumours, under the accidental cellular tissue of the serous mem- 

 branes. 



Accidental cartilages are sometimes formed by transforma- 

 tion of other tissues. An old woman who some years ago 

 was at the Hospital of the faculty of medicine at Paris, and 

 who had on her forehead a broad conoid horny production 



