CHAPTPm XIII 



PROTOZOAL PARASITES 



Herpetomoxas muscae-domesticae Burnett. 



The Herpetomonas of the house-fiy, Herpetonionas muscae- 

 domesticae Burnett, has been known for many years as a flagellate 

 parasite of the alimentary tract of M. domestica, but the discovery 

 of the relation to certain diseases of a number of species of Tiy- 

 panosomes and allied flagellates has been responsible for a con- 

 siderable addition to our knowledge of the life-history of this and 

 other species of flagellates inhabiting the alimentary tracts of 

 insects. 



In 1878 Stein figured a flagellate which he called Cercomonas 

 muscae-domesticae, identifying it with the Bodo muscae-domesticae 

 described by Burnett and the Cercomonas muscarum of Leidy. 

 For this form Kent (1880-81) instituted a new genus Herpetomonas. 

 When the haemo-flagellates were being studied some years later, 

 Prowazek (1904) described with great detail the development of 

 this species. In the previous year Leger (1908-1909) had given 

 a short account of the species. Patton (1908-1909) has also 

 described the life-history of H. muscae-domesticae, and his account 

 has been confirmed by Porter (1909), Mackinnon (1910) and 

 Wenyon (1911 and 1918) who in his later paper gives a careful 

 account of the cytology of the flagellate. 



The full-grown flagellate (fig. 77, VIII) measures 30-50 fx in 

 length. The body is flattened and lancet-shaped, the posterior 

 end being pointed and the anterior end bluntly rounded. The 

 alveolar endoplasm contains two nuclear structures. In the centre 

 is the large " trophonucleus " {tr.) ; it contains granules of chro- 

 matin, but is sometimes difficult to see. Near the anterior end 



