178 PROTOZOAL PARASITES 



(Ic.) found that the majority of house-flies at Aleppo, Sp-ia, 

 contained H. muscae-domesticae. Although fihus of the contents 

 of the alimentary tracts of a large number of house-flies were 

 made and examined by me at Manchester (England) I was unable 

 to find with any certainty these flagellates, nor was Dunkerly (I.e.) 

 more successful. 



One of the chief points of interest in connection with this 

 flagellate is its similarity to the parasite of Kala-azar. This re- 

 semblance prompted Rogers (1905) to suggest that the latter 

 parasite was a Herpetomonas which Patton has since not only 

 conclusively proved to be the case but has also shown that the 

 bed-bug can act as its carrier. 



Critiiidia muscae-domesticae Werner. 



Werner (1906) described this ptirasite jfrom the alimentary 

 tract of 3f. domestica, where he stated that it occurred in the 

 alimentary tracts of four out of eighty-two flies examined. 



It measures 10-13 //. in length, the length of the body being 

 5-7 /x and the flagellum 2-6 //. As in other members of the genus 

 Crithidia, which is closely allied to Herpetomonas, the breadth of 

 the body is great compared with the length, and the kinetonucleus 

 and trophonucleus are rather close together. A short, staining, 

 rod-like body lies between the kinetonucleus and the base of the 

 flagellum. The flagellum is single. Dividing forms undergoing 

 longitudinal division were frequently found. The kinetonucleus 

 appears to divide first, followed in succession by the flagellum and 

 the trophonucleus. Forms undergoing division and showing a 

 single trcjphonucleus and double kinetonucleus and flagellum were 

 also found. Cases occurred in which the fission began at the non- 

 flagellate end of the body. No conjugating forms were found, nor 

 any wandering into the ovaries. 



Lingard and Jennings (I.e.) describe certain flagellates of a 

 flag-shaped or rhomboidal nature, which I am strongly of the 

 opinion are species of Crithidia and not species of Herpetomonas. 

 Closely following Prowazek's account of H. muscae-domesticae they 

 describe and figure all their forms as having two flagellae in the 

 flagellate stage. If one allows for the rupture of the flagellum 



