INTESTINAL SCHISTOSOMIASIS 263 



The scolex has a typical rostelkim with three to four rings of hooks 

 and four unarmed suckers. The genitalia are double with spores on 

 each side. Ripe proglottides get into the fur where eggs infect the dog 

 and cat, louse or flea in which cysticercoids develop. The dog bites 

 the insect, gets the cysticercoid on its tongue and later licks man, thus 

 infecting him. Cats may infect milk when drinking from a household 

 vessel and children thus become infected. 



HYMENOLEPIS DIMINUTA. 



This parasite is common in rats and mice, rarely in children. 

 The cysticercus is found in the larva and the imago of the meal- 

 moth, earwig, and beetle. 



The adult is 20 to 60 cm. long by 3*5 mm. broad. 



It has an unarmed rostellum with four elliptical suckers. 



HYMENOLEPIS NANA. 



This is the dwarf tapeworm of man. It is widely spread in Egypt, 

 Europe, America, Siam and Japan. 



Ten per cent, of the children of Sicily are affected. 



It is 10 to 15 mm. long by o'6 mm. broad. The smallest tapeworm 

 in man. It has a rostellum Avith one ring of twenty-four to thirty 

 hooks, and also has a rather long neck. It has 150 proglottides. The 

 genital pore is marginal. The mature uterus contains about thirty 

 eggs. The cysticercus stage has not yet been found ; perhaps it is 

 passed in some insect. 



The symptoms in children may be nil or slight. 



In bad cases there is intestinal irritation and anaemia. 



Infected children should be isolated as infection spreads rapidly. 



Male fern should be given. 



There may be up to several thousand in one individual. 



DAYAINEA MADAGASCARIENSIS. 



This is found in children, but is not very important. 



It is 25 to 30 cm. long bv i'^ mm. broad. The scolex has four 

 suckers and a rostellum with ninety hooks. 



The proglottides number from 500 to 700, and are longer than 

 broad. 



The genital pores are unilateral, and are situated near the proximal 

 corner. 



The uterus is a many-coiled tube which, when mature, uncoils, 

 loses its wall, and the eggs, then free, become surrounded by cells 

 which form capsules for themselves. 300 to 400 of these capsules may 

 exist in one proglottis in transversp rows. 



