'24 Beport of the Bilharzia Mission in Egypt, 1915 



As every digenetic trematode hitherto investigated has been found 

 to undergo its larval metamorphosis in a mollusc, the deductions 

 made by Looss from investigations ranging over such a restricted 

 part of the molluscan fauna of Egypt are entirely unwarranted. 

 The conclusion of Lortet and Sonsino, that their inquiries had 

 failed to reveal the essential invertebrate intermediary, was much 

 more reasonable. 



The Present Inquiry. 



As the province of Qaliubia had been shown to be heavily 

 infected with bilharziosis it was decided to make Cairo the head- 

 quarters of the inquiry. It will be seen from fig. 1 that the province 

 of Qaliub adjoins Cairo immediately to the north, lying between 

 the eastern (Damietta) branch of the Nile on the west and the 

 desert on the east, and is easily accessible by road and rail, being 

 traversed by the highway and main line to Alexandria and their 

 subsidiaries. At the request of Sir David Semple, Chief of the 

 Public Health Department of Egypt, the vacant laboratories of the 

 Professor of Parasitology in the School of Medicine in Cairo were 

 kindly set apart for our use by the Director, and facilities for the 

 keeping of experimental animals were provided at the Bacterio- 

 logical Institute. The C.M.S. Hospital at Old Cairo constantly 

 supplied fresh material for observation from their clinical cases. 

 The programme of work laid down and consistently followed 

 was : — 



(a) To collect and specifically determine all the fresh-water 

 molluscs in the selected endemic area, i.e., within half a day's 

 journey from the laboratory in Cairo. 



(6) To dissect large numbers of all species found for trematode 

 larvae. 



(c) To differentiate among the larvse found those showing the 

 morphological characters peculiar to the bilharzia group. 



{d) To ascertain which, if any, species of mollusc showed 

 chemiotactic attraction for Bilharzia miracidia. 



(e) To induce experimentally infection of animals brought from 

 England with Bilharzia cercaria when found in the mollusc. 



(/) To ascertain experimentally v.'hether infection took place 

 through the skin or by the mouth or in both ways. 



{g) To ascertain experimentally the incubation period of the 

 disease. 



{h) To determine experimentally on infected animals the efficacy 

 of medicines, reputed to be of value on clinical grounds, to destroy 

 the bilharzia worms in the portal system. 



