CRITHIDIA EURYOPHTHALMI 363 



wards from the crop to the mid-stomach and pyloric expansion (Fig. 168, 

 2-7 and 13-18). 



3. Multiple division forms, which resemble the intracellular stages of 

 development of Trypanosoma lewisi in the flea (Fig. 200, 9). They occur in 

 the crop, and are presumably produced by growth associated with nuclear 

 multiplication of flagellates which have entered the lining cells, and which 

 by segmentation give rise to a number of flagellates corresponding with 

 the number of nuclei (Fig. 168, 8-9). 



4. Forms which are supposed to show a process of internal budding 

 (Fig. 168, 12). 



5. Binary fission forms of the usual type occurring in the crop and 

 pyloric expansion (Fig. 168, 7). 



6. Crithidia stages from the crop, which become free forms (necto- 

 monads) in the mid-stomach and pyloric expansion (Fig. 168, 15-18). 



7. Crithidia stages from the crop, which become attached forms 

 (haptomonads) in the mid-stomach and pyloric expansion (Fig. 168, 



13-14)- 



8. Final ovoid stages, which occur both in the mid-stomach and pyloric 

 expansion. They are formed by a process the converse of that which 

 occurred in the crop when the ovoid forms grew into the elongate crithidia 

 forms. They become encysted, and pass back to the rectum as infective 

 forms, to be passed in the faeces (Fig. 168, 19). 



The interesting feature of this infection is that the cycle takes place 

 comparatively far forwards in the gut, the final stages occurring in the 

 pyloric expansion of the stomach, and not in the hind-gut. The ovoid 

 encysted forms taken into the crop grow into the crithidia forms, which 

 reproduce in the usual manner by longitudinal division, by an intracellular 

 multiple segmentation, and by the curious internal bud formation. The 

 latter is quite unique, and has not been described by any other observer 

 (see p. 338). The crithidia forms produced in the crop pass back to the 

 mid-stomach and pyloric expansion, where they may attach themselves 

 to the lining epithelium or remain free. In either case, they retrogress 

 to form the small ovoid encysting bodies. The various stages are illus- 

 trated in the diagram given by McCulloch, but confirmation of the intra- 

 cellular stages and the internal budding process is required before they 

 can be finally accepted. 



Genus: Herpetomonas Kent, 1880. 



The genus Herpetomonas was created by Kent (1880) for a flagellate 

 of the house fly {Musca domestica), which was first mentioned by Burnett 

 (1851, 1852) under the name Bodo. The next record of the fly flagellate is 



