HYMENOLEPSIS 



6og 



Blanchard thinks that the cat spreads the parasite by infecting 

 milk with the cysticercoids when it steals a drink from a bowl, the 

 contents of which are afterwards given to children, 



Hymenolepis Weinland, 1858. 



Synonym. — Diplacanthus Weinland, 1858, nec L. Agassiz, 1842. 



T)Q^mi\ovi,—Dipylinidiince with small head, with armed, well- 

 developed, or unarmed, rudimentary rostellum. Neck long. Pro- 

 glottides serrated, longer than broad. Genital pores always on the 

 left. Three testes. Eggs with three shells. 



Type. — H. diminuta. The genus possesses two subgenera, 

 Hymenolepis and Drepanidotcsnia. 



Subgenus 1. Hymenolepis Sensu Stricto. 



With the characters of the genus, but the hooks have the dorsal 

 root much longer than the ventral, and number twenty-four to 

 thirty. 



Proglottis narrow, female genitalia ventral to or between testes. 



Hymenolepis (Hymenolepis) diminuta Rudolphi, 1819 . 



Synonyms. — -Tcenia diminuta Rudolphi, 1819; T. leptocephala 

 Creptlin, 1825; T. flavopunctata Weinland, 1858; T. varesina Parona, 

 1884; T. minima Gmssi, 1886. 



It is a parasite of Epimys norvegicus, E. musculus, and E. rattus 

 alexandrinus, being not uncommon in rats in Ceylon. 



The first human specimen was discharged by a child aged nineteen 

 months, and was presented to the Boston Medical Improvement 

 Society by Dr. Ezra Palmer in 1842. Since then a number of cases 

 have been recorded in Philadelphia, Sicily, Italy, France, South 

 America, and the West Indies. 



Morphology. — -The worm measures 20 to 60 centimetres in length, 

 and up to 3-5 millimetres in breadth. The head is very small, only 

 0-2 to 0*5 millimetre in diameter, club-shaped, and has a rudi- 

 mentary, unarmed rostellum and four elliptical suckers. The 

 segments measure o-66 millimetre in length by 3-5 millimetres in 

 breadth. The anterior proglottides show a yellow spot (hence the 

 name T. flavopunctata), caused by the distended receptaculum 

 seminis. The posterior proglottides show a brownish-grey colour, 

 due to the mature uterus. The genital pore is situated laterally. 

 The eggs are oval, with a diameter of about 60 ^. 

 \ Li£e-History. — ^It is a common parasite in rats and mice, while the 

 I cysticercus is said to live in the larva and imago of the meal-moth 

 \ {Asopia arinalis), in an earwig {Anisolabis annulipes), and in the 

 [ beetles Acis spinosa and Scaurus striatus, it is not likely that rat 

 I fleas are important, as the cysticercus has been found in Cerato- 

 phyllus fasciatus by Nicoll and Minchin, and Johnston in Australia 

 [, has found it in Xenopsylla cheopis. 



I The infection in man is mostly among infants and chi] dren . 

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