C. M. Wen YON 
335 
Fig. 13. Dividing flagellate. Within the kinetonucleus are the two granules which have 
not yet reached the sides of the kinetonucleus which appears to have a definite 
membrane. The two blepharoplasts clearly shown. 
Fig. 14. Dividing flagellate showing well the precocious formation of flagella. Though 
division is not complete the daughter flagella of the succeeding division are already 
forming. 
Fig. 1.5. Anterior end of a dividing flagellate showing blepharoplasts, rhizoplasts and 
diplosomes. 
Fig. 16. Anterior end of a dividing flagellate showing the dividing karyosome (?) within 
the kinetonucleus. 
Figs. 17-20. Dividing flagellates. Fig. 18 from a flagellate in which the kinetonucleus 
has been destroyed. It shows well the union of the rhizoplast and blepharoplasts by 
means of a faintly staining line. 
Figs. 21-36. A flagellate of trypanosome type from the malpighian tubes of the house¬ 
fly. They possibly represent forms of Herpetomonas muscae domesticae. 
Fig. 21. Dividing form. 
Figs. 22, 23, 27, 29, 31, 33-36. Various stages in the formation of the small pear-shaped 
forms (fig. 23) from the long forms (figs. 28 and 30). 
Fig. 24. Large dividing form. 
Fig. 25. Long dividing form without nucleus but still possessed of kinetonucleus and 
blepharoplasts. 
Fig. 26. Dividing form showing two granules within the kinetonucleus and two 
blepharoplasts. 
Fig. 28. Dividing form. 
Figs. 30 and 32. Typical long forms. Note the long drawn out flagellar extremity of the 
body. The kinetonucleus is always on the non-flagellar side of the nucleus. There 
is no free flagellum as this structure terminates at the blunt end of the body. 
is still single but close to its flagellar side are the products of the already 
divided blepharoplast. From the new blepharoplast a new rhizoplast 
narrower than the old one has formed, and this has grown out into the 
beginnings of a new flagellum. Patton believes that the new rhizoplast 
is divided off from the fresh one, but it is certainly a new formation 
growing out from the divided blepharoplast. The blepharoplast alone 
divides. Porter claims to have watched the division of the flagellum in 
the living Herpetomonas muscae domesticae. From the stained smears 
examined by me, I can find no evidence of such a division. The 
flagellum is enclosed, as I believe, in a thin sheath of ectoplasm con¬ 
tinued from the body of the flagellate and it is within this sheath that 
the new flagellum grows out. As the flagellum increases in length both 
it and the rhizoplast increase in thickness till eventually the length and 
thickness equal those of the old flagellum. Such stages may be followed 
in figs. 17, 12, 10, 13, 16, etc. When the new flagellum has attained a 
certain degree of developmept, indications of division appear in the kineto¬ 
nucleus. Within this there is apparently a structure like a karyosome. 
Parasitology iv 
22 
