1906.] Glossina palpalis and Trypanosoma gambiense, etc. 255 



numbers. In the third fly this Hcrpetomonas was present in very scanty 

 numbers and no trace of recently ingested blood could be found in it. 



Films, fixed in osmic acid and stained with Borrel blue and eosin, showed 

 that the commonest type of this parasite measures from 35 to 50 /^(figs. 2 — 4). 



Figs. 2 — 4. — Herpeiomonas from the gut of Stomoxys (ccdcitrans ?) ; fig. 2, common 

 form with single flagellum, and with nucleus broken up into separate 

 masses ; fig. 3, commonest form, with double flagellum ; fig. 4, form 

 with compressed nucleus and very long flagellum. 



The body of the parasite is cylindrical, with a rounded anterior and more 

 pointed posterior extremity. The protoplasm of the body stains rather 

 deeply. A large rounded nucleus is placed at the centre of the body of the 

 parasite. The chromatic substance of the nucleus is sometimes seen to be 

 broken up into granules (chromosomes), apparently 14 in number, contrasting 

 in this respect with H. muscce-cloviesticce, in the nucleus of which eight 

 chromosomes are present (Prowazek). The blepharoplast is oval or kidney- 

 shaped, of a large size and stains deeply. It is placed close to the origin of 

 the flagella and to the anterior rounded extremity of the body of the parasite. 

 The double flagellum arises close to the blepharoplast and may reach an 

 enormous length in some individuals (fig. 4). 



Besides these large forms, smaller individuals are present (figs. 5, 6, 7). 

 The bodies of these parasites stain more faintly than the above and are often 

 curved. The nucleus is more compressed. The blepharoplast is smaller and 

 situated at a greater distance from the anterior extremity of the body. The 

 single flagellum arises close to the blepharoplast and consequently has a 

 somewhat longer course through the body of the parasite. It emerges as a 

 short, thick, free flagellum. 



Both these forms commonly undergo longitudinal division. In some cases 

 the nucleus apparently divides before the blepharoplast. 



