202 ENTOZOA. 



saw tlie embryos escaping by a lateral slit near tbe anterior pole 

 of tlie shell. Whilst the ova are still within the body of the 

 parent, the embryos develop themselves into minute ciliated 

 animalcules, and after their escape they exhibit Hvely movements. 

 Many cihated embryos were found by Griesinger, free, in the 

 intestine of the human subject. According to Bilharz and Leuc- 

 kart, the embryos measure ^" in length, and ^" transversely. 

 They are extremely delicate in structure, being, for the most part, 

 transparent, and containing in their interior a quantity of fine, 

 highly refracting, sarcode globules. At the anterior end, which is 

 more or less pointed, Bilharz observed a double pyriform corpus- 

 cular mass, which would probably represent the rudiments of a 

 digestive pouch in the next stage of larval formation. Beyond 

 this point, however, we know nothing as to the precise forms which 

 the larvge of Bilharzia assume ; but it is, of course, highly probable 

 that their sporocystic and cercarian features correspond, in the 

 main, with those displayed by the larvEe of other trematodes. 



Injurious Effects upon Man. — The peculiar and formidable 

 helminthiasis produced by this parasite has been thoroughly in- 

 vestigated by Griesinger and Bilharz, and it is, hkewise, very fully 

 described in the standard works of Kiichenmeister and Leuckart. 

 The prevalence of the disease in Egypt has already been alluded 

 to ; and its principal feature consists in a general disturbance of 

 the uropoietic functions. Diarrhoea and hgematuria occur in 

 advanced stages of the complaint, being also frequently associated 

 with the so-called Egyptian chlorosis, cohcky pains, anaemia, and 

 great prostration of the vital powers. The true source of the 

 disorder, however, is easily overlooked unless a careful microscopic 

 examination be made of the urine and other evacuations. If blood 

 be mixed with these, and there also be a large escape of mucus, a 

 minute inspection of the excreta will scarcely fail to reveal the 

 presence of the characteristic ova of Bilharzia. Beside the increase 

 of mucous secretion, there may even be an escape of purulent 

 matter, showing that the disorder has far advanced. The whole 



