6 Report of the Bilharzia Mission in Egypt, 1915 



and those consequently concerned in the production of intestinal 

 lesions, while the name B. capensis was proposed by Harley for that 

 specially inducing vesical lesions. 



In 1893 Manson [828] suggested, on grounds of dissimilar 

 geographical distribution, that the vesical and intestinal forms 

 of the disease were of separate origin. Adopting this suggestion, 

 Sambon [4'25], in 1907, formally created a new species, Schistosomnm 

 mansoni, for the lateral-spined egg. Its validity was bitterly 

 criticized by Looss [290], and the exact relation of this new 

 name to the older specific names. B. hcematobia, B. capensis, and 

 B. viaqna, still remains to be finally established. 



The disease has been variously named : {a) After 

 the discoverer, bilharzia disease, bilharziosis, bilhar- 

 ziasis ; (6) after the generic name of the parasite, schistosomiasis ; 

 (c) after the chief clinical manifestations, e.g., endemic haematuria, 

 bilharzial dysentery, verminous cystitis. Cape ha3maturia, Egyptian 

 haematuria ; and {d) after the pathological situations, e.g., rectal 

 bilharziosis, hepatic bilharziosis. 



Bilharz does not appear to have made any 



t' ■ observations upon the life-cycle or the probable 



Intermediary. ^ . i c .v. -,• 



mode 01 spread or the disease. 



In 1854 Griesinger [200] conjectured that the young of Bilharzia 

 " existed in the waters of the Nile, in the fishes which therein 

 abound, or even in bread, grain, and fruit." 



Harley i214], in 1864, wrote " according to the observations 

 of Professor Siebold on the trematode worms, it may safely be 

 assumed that between the ciliated embryo above described and 

 the adult sexual animal there are probably two other distinct 

 forms which serve to complete the chain of metamorphosis con- 

 necting these two extremes of development. What these forms 

 are, and what their transmigrations, are questions which require 

 careful elucidation. The ciliated embryo is adapted for an aquatic 

 existence. Swimming freely about, these minute organisms probably 

 come in contact with certain inollusca and become developed within 

 them into wliat have been called cercaria sacs." 



In his text-book on " Entozoa," published in 1864, Cobbold [95], 

 after quoting Griesinger, remarks, " I think it is more probable 

 that tiie larv«, in the form of cercarite, redias and sporocysts, will 

 be found in certain Gastropod molluscs proper to the localities from 

 whence the adult forms have been obtained." 



The credit of having made the first attempts to trace the 

 life-cycle through an invertebrate intermediary must be given to 



