The Schistosoma (Distoma) Haematobium has two distinct sexual forms, the male and the female.

The male is the larger, is from 12 to 14 mm. long and 1 mm. thick. The female is longer and thinner, 16 to 18 mm. long and 0.13 mm. thick.

Fig. 117. - Human Blood Fluke (schistoma or dlstoma Haematobium). X 5 (Leuckart).

The female is partially within the canalis gynaecophorus of the male.

The eggs are oval, 0.12 mm. long, and somewhat pointed at the ends.

In the act of fecundation the female crawls into a canal formed by the curving up of the sides of the male.

These parasites occur in the portal, abdominal, and cystic veins. The eggs are produced in great numbers and obstruct and rupture the capillaries, thus escaping into the tissues. The wall of the bladder may become inflamed, ulceration take place, and eggs and blood escape in the urine.

The embryos are supposed to live in water and gain entrance by the alimentary tract and through the skin.