198 ANNIE POJiTER. 



lated (PI. 12, tigs. ]8, 19) in the crop, or the small forms 

 produced by division prior to eiicystment (PL 12, figs. 20, 

 21; 99) are very much smaller 02 fi to 20/^1 long). The 

 breadth of the flagellates varies from I'o^ to 2'H n. 



The protoplasm of C. melophagia is very slightly alveolar 

 or almost hyaline, differing therein from the more alveolar 

 protoplasm of C. gerridis. There is no suggestion of large 

 permanent vacuoles or of a cyto-pharynx. Occasionally the 

 protoplasm is more granular at the posterior end (PI. 12, figs. 

 80, 34) and slight alveolation occurs there. At the anterior 

 end, near the origin of the flagellum, the remains of the 

 chromatic area, from which the flagellum arose, sometimes 

 persist. 



The nucleus (trophonucleus) of C. melophagia is oval 

 (PI. 12, figs. 2 1-24 J or rounded (figs. 20, 30, 32) and some- 

 what vesicular. There is a fair amount of chromatin present, 

 which may consist of a number of very fine granules, evenly 

 distributed (fig. 32), or the chromatin may be conceuti*ated 

 into about eight masses (fig. 44), or, as is often the case, the 

 chromatin is present in the form of bars (tigs. 25-29), which 

 sometimes extend across the whole breadth of the uucleug 

 (figs. o4-37j, less frequently across part of its breadth 

 (figs. 24, 42), or in an even more rare condition dots and 

 bars occur in the nucleus of the same oi-ganisra (figs. 30, 39). 

 In certain cases the chromatin of the nucleus may be con- 

 centrated into a central mass (tig. 23). 



The nuclear membrane is fairly distinct in most of the 

 specimens I have examined. I think that such a membrane 

 must be present to keep together the nuclear material during 

 the migrations of the nucleus seen during life. 



The blepharoplast (kiuetonucleus) of C. melophagia 

 is very evident in a stained preparation, for it colours deeply 

 whatever stain be employed. Like the nucleus, it can also 

 be seen in life as a small bright retractile bar. In some 

 cases it is slightly bowed or curved (PI. 12, fig. 32), or oval 

 (PI. 12, fig. 34). It is dumb-bell-shaped in forms about to 

 divide (PI. 12, fig. 44). The blepharoplast, which is typically 



