:86 PRESIDKNTIAL ADDRESS— SKCTIOX D. 



In South Africa, I liave been able to work out the hfe-histoi-y 

 of a bird Ecliinostonie, provisionally named Echinostoma fulicce, 

 parasitic in the adult stage in the red-knobbed coot, Fulica 

 cristata. This Trematode was described in some detail last year, 

 and 1 now just mention that the larval stages are passed in either 

 of the snails, Isidora tropica or Toitisia vcntncosa. The cercarise 

 have a simple tail, with a pegtop-like terminal portion. Encyst- 

 ment takes place on the outside edge of the mantle, in the liver 

 and on the outside shell of the snail. These snails are devoured 

 by the coot and the adult develops in the intestine of the birds. 



Eecently, Dr. Cort has drawn attention to a report by Dr. 

 Tanabe of the occurrence of Ecliinostoma perfoliatum var. 

 japonicinn in man, and of the outlines of its life-cycle being 

 established. Tanabe fed clean dogs with encysted echinostomes 

 found in certain fresh- water fish (of which the kinds are not given 

 in Cort's notice), and as a result he obtained adult flukes from 

 the dogs. Later, he found eggs of an echinostome in human 

 faeces, and surmised that they came from the same kind of 

 worms that he had produced experimentally. He then ate some 

 of the cysts from the fish and produced the flukes in himself, 

 thus proving that the cyst-bearing fish were the second inter-' 

 mediate hosts of Echinostoma perfoliatum var. japonicum. 



The life-history of the cattle and sheep fluke, Fasciola 

 hepatica, was worked out by Thomas and by Leuckart in classical 

 researches published in 1882-3. In Europe the intermediate host 

 is Limricea truncatula ; in Sovith Africa, I have been able to 

 prove that the molluscan hosts of the fluke are Limncea natalensis 

 and Isidora tropica* The first-mentioned snail is also the South 

 African transmitter of Fasciola giijantica,] as I have experi- 

 mentally shown. 



That man may become infected with Fasciola hepatica and 

 F. gigantica is, perhaps, not so well known, but a number of 

 cases of infection with Fasciola hepatica have recently been 

 reported. Senevet (1920) records a case in a Erench soldier, who 

 had served in the Dardanelles, Mudros and Salonika. De 

 Lavergne had a case in an invalided French soldier. Mauriac and 

 i^oyer (1921) tried to treat a patient infected with Fasciola 

 hepatica with tartar emetic, but their patient — and also some 

 infected sheep treated at the same time — made no improvement, 

 and death ensued. Guiart also reports a case of infection in a 

 Erench soldier, who contracted the infection in Salonika. In all 

 probability the eating of green salads or uncooked fruit or 

 vegetables on which encysted flukes occurred was responsible for 

 this intractable human infection. 



Ancylostomiasis. 

 Among the Nematodes, there are a number whose life- 

 histories have been known for some years. Thus, in the cases 

 of Ancylostoyna duodenale and Nccator americana, their life- 

 histories having been elucidated, attention has been focussed on 



* South African Journal of Science, xviii, p. 159. 

 t Ibid., xvii, pp. 126—130. 



