96 



CYSTICEBCUS FASCIOLARIS TJENIA TENLffiFOBMIS. 



[Fig. 22.] 



This encysted larval tapeworm is exceedingly common in the liver 

 of rats and mice, and when swallowed by cats it develops into an 

 adult tapeworm. 



There are two possible points of view in connection with which this 

 parasite is of indirect interest in public-health matters: (1) Occasion- 

 ally these encysted parasites are mistaken for lesions of tuberculosis; 

 (2) Krabbe (1880) relates that in Jutland there exists a folk custom 

 of eating chopped raw mice in case of retention of urine, and in this 

 connection the point has been raised that the possibility is not 

 excluded that such action might eventually give rise to infection of 



FIG. 22. Larval stage of Tsenia tenisejormis. Natural size. (After Leuckart, 1880, 450, fig. 202.) 



man by the parasite in question. No case of such infection in man is 

 as yet established. 



HYMENOLEPIS MUBINA (Dujardin, 1845)=HYMENOLEPIS NANA 

 FBATEBNAa Stiles, 1906. 



[Figs. 23 and 24.] 



Under the name Tsenia murina, Dujardin (1845) described for rats 

 a tapeworm which has been identified by a number of authors (includ- 

 ing Stiles) as identical with the dwarf tapeworm (Hymenolepis nana) 

 of man. If this identification be correct, the rats must be considered 

 as the great disseminators of this tapeworm. Serious doubts have 

 been raised, however, as to whether the tapeworm in man is not in 

 reality distinct from that of the rat, and the evidence in favor of such 

 conclusion is accumulating. Some slight differences between the two 

 forms have been noticed, but by some authors these differences have 



a SYNONYM. Tsenia murina Dujardin, 1845 (not Gmelin, 1790). 



