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Some Notes on the Differentiation of closely-allied Schistosomes

Published online by Cambridge University Press:  06 April 2009

F. G. Cawston
Affiliation:
First Streatfeild Research Scholar, Durban, Natal.

Extract

When fresh-water snails are examined microscopically, specimens are occasionally encountered that are infested with the cercariae of more than one species. Sometimes these cercariae are easily differentiated. A snail may harbour numerous eye-spotted amphistomes and a few distomes without eye-spots, or furcocercous forms may be associated with cercariae possessing undivided tails. In some collections of semi-stagnant water, however, the same individual snail may be found infested with at least two distinct schistosomes. In 1916, I found Physopsis africana (in an overflow pool along the course of the Umsindusi river at Pietermaritzburg) heavily infested with two distinct schistosomes, and it was not uncommon, as Dr E. E. Warren also observed, for the two forms to develop in the same host. One of these cercariae I named Cercaria secobii, the other was probably the cercaria of Schistosoma haematobium. Soparkar (1921 a and b) has moreover noted a double infection of Planorbis exustus near Bombay.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1922

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References

Cawston, F. G. (vii. 1917). The Cercarial Infection of South African Snails. Med. Journ. of South Africa, XII. No. 12.Google Scholar
Cort, W. W. (1918). Adaptability of Schistosome Larvae to New Hosts. Journ. of Parasitol. IV. 171173.CrossRefGoogle Scholar
Faust, E. C..(vi.1920). Criteria for the Differentiation of Schistosome Larvae. Journ. of Parasitol. VI. 192194.CrossRefGoogle Scholar
Faust, E. C. (ix. 1920). A Survey of Cawston's Species of S. African Cercariae. Parasitology. XII. 212216.Google Scholar
Faust, E. C. (ix.1921). The Present State of the Schistosome Problem. China Med. Journ. XXXV. No. 5.Google Scholar
Leiper, R. T. (18.iii. 1919). On the relation between the Terminal-spined and Lateral-spined eggs of Bilharzia. Brit. Med. Journ.Google Scholar
Porter, A. (i. 1920). The Experimental Determination of the Vertebrate Hosts of some S. African Cercariae from the Molluscs Physopsis africana and Limnaea natalensis. Med. Journ. of South Africa, XV. 128130.Google Scholar
Soparkar, M. B. (vii. 1921 a). Notes on Some Furcocercous Cercariae from Bombay. Indian Journ. Med. Res.Google Scholar
Soparkar, M. B. (vii.1921 b). The Cercaria of Schistosomum spindalis (Montgomery). Indian Journ. Med. Res.Google Scholar