50 TROPICAL MEDICINE AND HYGIENE 



DIPYLIDIUM. 



Dipylidium is a genus in which the genital organs 

 are duplicated. As in all the Taeniidae, the genital pore is 

 lateral, and the two sets of genital organs open on to the 

 opposite edges of the proglottis (fig. 24, B). The common 

 dog tapeworm, Dipylidium caninum, belongs to his class. 



FIG. 24. A, Tcenia saginala ; B, Dipylidiuni; c, Davainea j D, Hymeno- 

 lepis ; E, Bothriocephalus ; F, Diplogonoporus grandis. 



Dipylidium caninum is an accidental parasite of man, 

 and though not very common is found all over the world, 

 and perhaps more commonly in the Tropics than else- 

 where. Only children seem to acquire the infection. In 

 these cases the segments are nearly always passed singly 

 with the motions, and on account of their small size and 

 active movement their nature may not be recognized. 

 They do not seem to cause any symptoms and are readily 

 expelled by anthelmintics. 



As the cysticercoid stage is passed in the dog-flea and 



