HYMENOLEPIS 225 



anus and get into the fur, and are thus transmitted by their hosts. 

 Part of the segments, or the oncospheres released by disintegration, 

 are then taken up by the lice and fleas, within which they develop 

 into cysticercoids. Dogs and cats are thus infected by their own 

 skin-parasites, which they bite and swallow whilst gnawing at their 

 fur. The infection of human beings must occur in an analogous 

 manner, by transmission of the cysticercoids present on the lips or 

 tongue of dogs when licking them, or it may be that the vermin of 

 cats and dogs harbouring cysticercoids infect human beings direct. 



LITERATURE. 



LEUCKART, R. D. menschl. Paras., 1863, i., p. 400. 



STEUDENER, F. Unters. iib. d. fein. Bau d. Cest. (Abh. nat. Ges. Halle, 1877, 



xiii., p. 295.) 

 DIAMARE, V. II genere Dipylidium. (Atti R. Ace. sc. fis. e mat. Napoli., 1893, 



ii., Ser. 2, No. 7.) 

 MELNIKOW, W. Ueb. d. Jugendzust. d. T. cucum. (Arch. f. Naturg., 1869, 



xxxv., i., p. 62.) 

 GRASSI, B., and G. ROVELLI. Embr. Forsch. a. Cest. (C. f. B. u. P., 1889, 



v., p. 370.) 

 Ric. embryol. sui Cest. (Atti Accad. Gioen. sc. nat. Catania., 1892, Ser. 4, 



vol. iv. ) , 



SONSINO, P. Ric. s. ematoz. del cane e sul ciclo evol. d. T. cucum. (Att. soc. 



tosc. sc. nat., 1888, x., p. i.) 

 SALZMANN. Ueb. d. York. d. T. cue. i. Mensch. (Jhrshfte. d. Ver. f. vaterl. 



Naturkde. Wiirtt., 1861, xvii., p. 102.) 

 HOFFMANN, A. Taen. cue. b. ein. 4 Monate alten Kinde. (Jahrb. f. Kinderhlkde, 



N. F., 1887, xxvi.) 



KRUGER, F. St. Pet. med. Wchschr., 1887, No. 41. 



BRANDT, ED. 2 Falle v. T. cue. b. Mensch. (Zool. Anzgr., 1888, xi., p. 481.) 

 TRIIS. Nord. med. Arkiv., 1884, xvi., No. 6. 

 BLANCHARD, R. Trait. Zool. med., 1889, i., p. 481 ; and Mai. Paras., 1895, 



p. 718. 



Gen. 4. Hymenolepis, Weinland, 1858. 



The scolex is small ; rostellum armed ; suckers unarmed ; the neck is 

 long ; the breadth of the segments is greater than their length. The 

 genital pores He all on the left. Three testes in each proglottis. The mature 

 uterus fills the entire segment ; the eggs are round or oval with three 

 distinct envelopes. Found in mammals and birds. 



The genus -has recently been divided into two sub-genera Hymenolepis, 

 s. str., and Drepanidotcenia, Raill. 



[The following are the characters of the two genera, Hymeno- 

 lepis, Weinland, 1858, and Drepanidotcenia, Railliet, 1892.] 



Genus Hymenolepis, Weinland, 1858 (Diplacanthus, Weinland, 

 1858 [nee L. Agassiz]). 



Head small, provided with retractile rostellum, well developed and armed 

 with a single crown of 24 to 30 hooks, or rudimentary or unarmed. Neck 

 long. Segments serrated, longer than broad, seldom less than 150 in 



15 



