DIBOTHRIOCEPHALUS 



309 



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

 infected. The symptoms, especially 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 in 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 five were from the U. S. 



H. lanceolata is common in geese and ducks. 



Dipylidium canimim (Taenia cucumerina) (T. flavopunctata). This is a common 

 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 booklets. 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 90 booklets. The suckers have rings of booklets. 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 /^ by 3^ 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- 



