574 THE DIGESTIVE SYSTEM. 



Gelatinous Carcinoma is not infrequent and sometimes seems to be 

 primary in the peritoneum. But in such cases the possibility of an origin 

 in the mucous membrane of the colon, in which such growths are com- 

 mon, and the extension outward without evidence of growth in the gut 

 is not improbable. Gelatinous cancer often forms large masses, which 

 widely involve the peritoneum and distend the cavity. 



Various forms of tumors of the umbilicus have been described. ' 



CYSTS. 



Cysts of the mesentery are of occasional occurrence. 2 They may be 

 filled with chyle, with blood, or with serous fluid, or may be due to the 

 echinococcus. 



Multiple cysts of the omentum may form by transplantation of papillary 

 cyst-adenomata from the ovary (see Fig. 349).'' 



Dermoid cysts may be found in the peritoneal cavity. Eetroperitoneal 

 cysts have been a few times recorded. 



PARASITES. 



Echinococci can be formed in their regular way at any part of the 

 visceral and parietal peritoneum, or be free in the peritoneal cavity. 

 These cysts may be small, or so large as nearly to fill the abdominal 

 cavity. 



Cysticercus cellulosae may also be developed in the subperitoneal con- 

 nective tissue. 



The Salivary Glands The Parotid, Submaxillary, and 

 Sublingual. 



INFLAMMATION. 



Acute Parotitis, occurring as an epidemic disease known as mumps, 

 is usually confined to the parotid gland of one side ; the submaxillary and 

 sublingual may be at the same time involved. The gland is swollen and 

 there is often osdema of the mucous membrane of the mouth and pharynx. 

 Very little is known of the minute changes which the gland undergoes in 

 this disease. 



Suppurative Parotitis occasionally occurs as a secondary lesion in a 

 variety of diseases, as in typhoid and scarlet fever, pyaemia, pneumonia, 

 etc., and by propagation of inflammation from the mouth. Under these 

 conditions the inflammation is usually suppurative and frequently results 

 in abscess or sloughing. The interstitial tissue of the gland is more or 

 less densely infiltrated with pus cells, and the parenchyma cells may un- 



1 See Gianwttasio, Arch. gen. de Med.. t. iii., p. 52, 1900. 



2 For bibliography of cysts of the mesentery see Dowd, Annals of Surgery, vol. 

 xxxii., p. 461. 1900. 



3 For bibliography of cysts of the omentum see Jacobi, Trans. Assn. Am. Pliys , 

 vol. xvi., p. 232. 



