224 



THE ANIMAL PARASITES OF MAN 



c.p.i 



FIG. 151. Dipylidium caninum. Central portion of a pro- 

 glottis (magnified). (After Neumann and Railliet.) C.p., cirrus 

 pouch ; V.s., vitellaria ; Ex.v., excretory vessels ; T., tes- 

 ticular vesicles ; O., ovary ; U., reticulum of uterus ; V., vagina. 



in which it grows larger (Tcenia cucumerina, Bloch) than in cats 



(T. elliptica, 

 Batsch) ; it has, 

 however, also 

 been found in 

 jackals, as well 

 as in human 

 beings, though 

 in the latter it is 

 of comparative- 

 ly rare occur- 

 rence (twenty- 

 four cases), and 

 almost always 

 affects children, 

 generally of ten- 

 der age. Only 

 one case affect- 

 ing an adult is known. The 

 proglot tides, which leave the 

 intestine spontaneously, are 

 recognisable by the naked 

 eye on account of their form 

 and colour, as well as their 

 two genital pores. As a rule, 

 the presence of this parasite 

 sets up no marked symptom 

 in the patient. 



The corresponding cysti- 

 cercoid lives in the louse of 

 the dog (Trichodectes canis), 

 a fact that was first esta- 

 blished by Melnikow and 

 Leuckart ; according to Grassi 

 and Rovelli, as well as Son- 

 sino, it also lives in the flea 

 of the dog (Pulex serraticeps) 

 and in the flea of man 

 (Pulex irritans), but not in 

 its larva. The adult seg- 

 ments, which leave the rec- 

 tum of the dogs and cats spontaneously, creep about around the 



FIG. 152. Cysticercoid of Dipylidium can- 

 inum (enlarged). (After Grassi and Rovelli.) 



