CAECINOMATA. 461 



naked eye, the progressive!}" increasing thickness of the muscu- 

 lar bundles as we pass from the healthy to the diseased tissues. 

 If we add to this the amount of additional matter produced by 

 the cancerous degeneration of the interstitial tissue, we can be 

 at no loss to account for the muscular coat attaining from three 

 to five times its normal thickness. 



Having traversed the muscular coat, the cancer reaches the 

 visceral peritoneum. The first nodules then make their 

 appearance in the subserous connective tissue. Their arrange- 

 ment often shows very clearly their original dependence on the 

 course of the muscular fasciculi ; i.e. they lie parallel to these, 

 in lines which correspond to the intermuscular septa of con- 

 nective tissue. Soon, however, the adjacent nodules coalesce 

 with one another, and we get irregular, flattened lumps, wdiich 

 present the special characters of the particular variety of cancer 

 to which they belong, in their least complicated form. 



This extension to the peritoneal coat is almost alwaj^s the 

 signal for a general degeneration of the entire sac. It is probable 

 that the mutual friction of the viscera may detach bits of the 

 cancerous nodules and carry them hither and thither over the 

 smooth surface of the membrane, until they find their way into 

 some fold or recess where they give rise to the development of 

 a fresh nodule. The general effect — as Virchoiv puts it — is that 

 of seeds having been scattered over the peritoneal surface, falling 

 here and there, and germinating. In this respect, soft and 

 scirrhous cancer behave in precisely the same way. The colloid 

 variety takes up a position of its own in this as in other matters ; 

 it performs the giant task of converting the wiiole peritoneum 

 into a mass of colloid cancer, continuously, without any break, 

 by a simple process of infiltration. The thickness which a single 

 peritoneal lamina attains w^hen the infiltration is completed, 

 amounts to two or even three lines ; the omentum, as a duplica- 

 ture of the membrane, is converted into a plate an inch thick, 

 and as hard as a board ; the mesentery and the various ligaments 

 follow suit. It is self-evident that under such conditions, the 

 most important disturbances of peristaltic action are unavoid- 

 able. The phenomena are usually complicated, moreover, b}^ in- 

 flammatory accidents, by an abundant sero-fibrinous exudation, 

 by small haemorrhages and adhesions. Similar accidents also 

 occur in the course of soft and scirrhous cancer. The scirrhous 



