1917] McCulloch: Crithidia euryophthalmi 81 



Fig. 10. Elongate flagellate showing structures common to these forms: /?., 

 flagellum; U7id. m., undulating membrane; bl., blepharoplast ; par. rh., parabasal 

 rhizoplast ; par. h., parabasal body ; rh., rhizoplast ; n., nucleus. 



Fig. 11. A discarded flagellum and parabasal body Avith one of the zooids 

 showing the results of the internal budding process of figvire 12. 



Fig. 12. Modified form of multiple fission designated as internal budding, 

 flagellum and parabasal body present, zooids in the parent body. 



Figs. 13-19. From near the entrance of the pyloric expansion. Fig. 13. An 

 attached or haptomonad form found on wall near entrance to the pyloric expan- 

 sion. Figs. 14-15. Nectomonad or free forms. Figs. 16-18. Haptomonad forms. 

 Fig. 19. Oval spore form. 



Figs. 20-27. Forms from the pyloric expansion. Figs. 20-22. Haptomonads 

 or attached forms. Figs. 23-26. Nectomonads or free forms. Fig. 24. Binary 

 fission form. Fig. 27. Oval spore form. 



Figs. 28-35. Oval spore forms from the rectum. Probably the infective forms 

 of C. euryophthalmi. 



The Hind-gut. — The hind-gut is composed of two parts, the colon 

 and the rectum. The colon is a thin, transparent, three-lobed structure 

 (fig. 1, c). Into each of the two lateral lobes opens one of the mal- 

 pighian tubules (fig. 1, m. t.), while the apex of the middle lobe is 

 joined to the intestine. 



The rectum is an almost transparent, ovoidal structure with the 

 larger end toward the colon. It gradually tapers down to a narrow 

 tube leading to the anal opening. The rectum is found either col- 

 lapsed, or greatly distended with a clear brown liquid. 



Infection of the Digestive Tract of Euryophthalmus convivus 



BY C. euryophthalmi 



Three parts of the digestive tract, the fore-, mid-, and hind-gut, 

 were carefully examined, each part separately, for flagellates. The 

 examination of the several parts of the fore-gut, namely : the 

 oesophagus and proventriculus, has always jaelded negative results. 

 The hind-gut has shown a slight infection in the rectal portions in 

 a few instances, but the mid-gut has in almost every case shown a 

 heavy infection of C. euryophthalmi in one or more of its several 

 parts. This heavy infection may be either in the crop, the mid- 

 stomach, or in the pj'loric expansion. Few adults are free from 

 great masses of attached parasites completely covering the inner 

 surface of the pyloric expansion. When this condition exists there 

 is little evidence of an epithelial lining to be found in this division 

 of the mid-gut. 



The stud3" of the stages of the life cycle of the flagellate shows 

 that those stages normally found in the rectal portion of other Hemip- 



