258 FLAT WORMS 



It has been estimated that in certain parts of Italy 10% of the children may be 

 infected. The symptoms, expecially nervous ones, may be marked in this infection. 

 It has been incriminated as a cause of chyluria. Although very small, yet the num- 

 ber of parasites may be very great, even more than 1000. In a case that I treated 

 with thymol there were 1500 worms expelled. A form found in rats, which may be 

 identical with H. nana, does not require an intermediate host. The six-hooked 

 embryo bores into the intestinal villus and there develops a Cercocystis (larva of 

 small dimensions with but little fluid). When fully developed, it drops into the 

 lumen of the gut, and a new parasite is added to the already existing number of 

 parasites. This explains the heavy infection. H. diminuta and H. lanceolata have 

 also been reported for man a few times. 



H. diminuta is much larger than H. nana, being about 10 inches long. The 

 suckers are small and the rostellum insignificant and unarmed. The intermediate 

 host is some insect, as a moth; the definitive, the rat. As man is not liable to eat 

 the insect hosts the infection is rare in man. Twelve cases have been reported for 

 man of which 5 were from the U. S. 



H. lanceolata is common in geese and ducks. 



Dipylidium caninum (Taenia cucumerina) (T. flavopunctata) . This is a com- 

 mon parasite of dogs and cats. The larval stage is passed in lice .and fleas. The 

 cases of human infection have been principally in children, probably from getting 

 dog lice or fleas in their mouths. The number of infections reported for man is 

 about 40 and of these about 30 in children. The head has four suckers and a 

 rostellum, which has three or four rows of encircling hooklets. The segments have 

 the shape of melon seeds and have bilateral genital pores. 



Davainea madagascariensis. This tape-worm has been found in Siam and 

 Mauritius. It is about 10 inches long. The head has four suckers and a rostellum 

 with ninety hooklets. The suckers have rings of hooklets. The genital pores are 

 unilateral. The cockroach is supposed to be the intermediate host. 



There have been about 10 cases reported (Madagascar, Siam and British 

 Guiana). There has also been reported a D. asiatica, the single specimen, however, 

 lacking a head so that the exact genus is doubtful. It has been reported twice in 

 children in Breslau. The intermediate host is thought to be a cyclops. Garrison 

 reported cases from the Philippines. 



DlBOTHRIOCEPHALID^E INFECTIONS. 



Dibothriocephalus latus (Bothriocephalus latus). This is fre- 

 quently termed the broad Russian tape-worm. It has a small olive- 

 shaped head with two deep winding suctorial grooves on each side ; it has 

 neither rostellum nor hooklets. 



The segments are quite broad., being about 1/2 by 1/5 inch. At the end of the 

 strobila they are more nearly square. The segments are very numerous, 3000 or 

 more. The fully developed worm is about 30 feet long. The uterus in each segment 

 is rosette-shaped and the genital pore is ventrally situated. The eggs of this species 

 have an operculum and a ciliated embryo. This ciliated embryo swims around and 

 either enters some fish, especially pike, directly or through an as yet unknown inter- 



