384 SUiMMARY OF CURRENT RESEARCHES RELATING TO 



and A. megalocephala lias been isolated a highly toxic albumose-peptone 

 (" Askaron "). It produces symptoms like those associated with infection 

 with Ascarids. It is present in Filaria iminitis, Sderosfomum vulgare, 

 Oxyuris curvula, and Trkliocephalus depress iusculus ; and also in bot 

 larvas. Horses are the most susceptible ; then, in descending order, 

 guinea-pigs, dogs, and rabbits. Eats and mice are refractory. After 

 poisoning with Askaron a high specific cellular resistance is rapidly 

 established. J. A. T. 



Platyhelminthes. 



Cestodes of Hilsa. — T. Southw'ell and Baini Prashad (Records 

 Indian Museum, 1918, 15, 77-88, 2 pis.). In the lateral muscles of 

 the anadromous fish Hllsa iltsha were found larval (cystic) stages of 

 Rhyncliohothrium ilisha sp. n. ; and practically all stages between these 

 and the adult tapeworms were found in the intestine of the shark 

 Carcharinus gamjeticus which had swallowed the Hilsa. This is the 

 first case in which the life-history of an Indian Cestode has been 

 worked out. The cysts, containing the young tapeworm, consisted of a 

 club-like head and a long tail-like structure which was capable of con- 

 siderable movement, and appeared to help to moor the parasite in the 

 intestine, or to retain it in the lumen until the young tapeworm had 

 time to emerge. Cysts of Syndesmobothriumfilicolle were also found in 

 the lateral muscles of Hilsa. The mesentery and liver yielded an 

 interesting doubtful form, provincially named Ilisha partlienogenetica. 

 The generic characters are : — Small parasitic leaf -like worms occurring 

 in cylindrical cysts. Anteriorly there is a rostellum with four unarmed 

 suckers symmetrically arranged round its base. Sexual organs and 

 pores are absent. The development is parthenogenetic. The young are 

 quite like the adult, and find their way out of the parent, and repeat 

 the same life-history. J. A. T. 



Hymenolepis nana Siebold and H. murina Dujardin. — F. H. 



Stewart {Records Indian Museum, 1916, 12, 295-8, 2 pis.). Some 

 authorities regard H. nana in man as only a dwarfed variety of 

 H. murina in the rat ; others regard them as distinct species. If the 

 two are identical it is probable that man is infected as a rule by the 

 contamination of food by rats. The author was unsuccessful in trying 

 to infect two rats with H. nana from man, and this negative result 

 suggests that the two species are distinct. A short account is given of 

 microscopic sections of H. nana, with especial reference to the repro- 

 ductive organs. J, A. T. 



North-American Trematodes. — H. W. Stunkard {Illinois Biol. 

 Monographs, 1917, 3, 287-39-4, 11 pis.). This paper deals with the 

 structure and relationships of Polystomidae (differing from all other 

 known Heterocotylea in being endoparasitic), Aspidogastridaj (both 

 ectoparasitic and endoparasitic, of direct development or with an inter- 

 mediate host, as adults found in both vertebrates and molluscs), and 



