SCHISTOSOMA H^MATOBIUM 275 



undergoes diffuse sclerosis, becoming hard and fibroid. Eventually 

 ulcerative necrosis sets in. During these changes the Lieberkiihn 

 glands are destroyed. The process does not extend to the submucosa, 

 in this respect differing from that in chronic dysentery. 



Hyperplastic Form. The Lieberkiihn glands of the mucosa at first 

 hypertrophy ; then there is an actual hyperplasia resulting in adeno- 

 mata. The interstitial tissue of the glands is also greatly hyper- 

 trophied, giving rise to very vascular granulations. These growths 

 are often hollow and contain worms. Many eggs are found in the 

 mucosa on their way to the lumen of the gut. 



The muscularls mucosa is thickened up to twice or even ten times 

 the normal. Its vessels are dilated (36 //, to 80 //,), but they do not 

 allow of the passage of worms. 



The submucosa is profoundly changed ; rigid and hard instead of 

 supple. It is here that the greatest number of eggs occur. A re- 

 markable condition of endophlebitis exists in the veins of the 

 submucosa, not only in the smaller ones but also in the larger ones 

 (370 yu, by 270 //,). This endophlebitis results in a more or less complete 

 occlusion of the vessels of the lumen. 



The muscular coats are free from change, also their veins. 



The Serous Coats. The veins about 1,900/1, also show endophlebitis. 

 Besides the rectum, in extreme cases even the transverse colon, the 

 caecum and small intestine may be affected. 



Bladder. In the early stages the mucosa is deep red and swollen 

 like velvet, or there may be localized patches of hyperaemia or 

 extravasation. The subsequent changes take two chief forms : 



(1) Sandy Patches. The mucosa ooks as if it were impregnated 

 with a fine brownish or yellowish powder (myriads of ova). This is 

 accompanied by a gradual hypertrophy and new formation of con- 

 nective tissue, so that dry, hard or plate-like patches with this sandy 

 appearance arise; the thickening eventually affects all the coats of 

 the bladder. In the older patches many of the eggs are calcified. 

 These patches sooner or later break down, ulcerate and necrose. 

 Phosphatic deposits are abundant and stone is common. These 

 patches are not found in the rectum. 



(2) Papillomata. Where the inflammatory change produced by 

 the eggs gives rise to hypertrophy and hyperplasia of the mucosa, 

 papillomata result, the axis of whicli is formed by connective tissue 

 of the submucosa. These are most variable in shape and form and 

 bleed readily, and sometimes contain cavities of extravasated blood. 



As in the rectum, it is in the submucosa that eggs are most 

 abundant, and worms in copula occur in the veins of this layer, but 

 endophlebitis is not as general as described in the rectum. Malignant 

 disease of the bladder is not an uncommon sequela of bilharziasis. 



