C. M. Wen YON 
333 
flagellate as having a peculiar arrangement of the flagella. Each flagel¬ 
late had a nucleus and kinetonucleus, the latter being often elongate 
with the long axis parallel to that of the body. Two rhizoplasts were 
present and each terminated at the anterior end of the body in a small 
granule termed a diplosome. From each diplosome arose a flagellum. 
The two flagella were attached to one another by some connecting 
substance or a membrane between them. In division one flagellum 
goes to each daughter flagellate and a new flagellum is formed by 
forward growth from the diplosome while the new rhizoplast grows 
backwards from the same structure. Patton has shown that in this 
flagellate the biflagellate arrangement is merely a stage in the longi¬ 
tudinal division. This is quite correct and I think that the various 
stages in this division which I have found completely establish Patton’s 
contention. Mackinnon and Porter also have come to a like conclusion 
and agree with Patton that the flagellate of the house-fly is not a bi¬ 
flagellate, but that the appearances described by Prowazek are merely 
division stages. 
A reference to the Text-figures 9 et seq. will make this matter clear. 
It will be seen that in all essential respects this flagellate (figs. 9 to 20) 
agrees with that of Prowazek and Flu. All the figures are drawn from 
films made from house-flies in which active multiplication of the 
flagellate was taking place. In other house-flies such a multiplication 
may not be in progress and the flagellate is then found with an 
elongated body, a nucleus and kinetonucleus which is much longer than 
broad, and a blepharoplast near the kinetonucleus from which arises the 
single rhizoplast which is continued into the single long flagellum. 
A vacuole is frequently present near the kinetonucleus and in many 
cases at the junction of the rhizoplast and flagellum is found a granule 
or enlargement of either of these structures which corresponds with 
the diplosome of Prowazek and Flu. The blepharoplast as a structure 
distinct from the kinetonucleus was not noted by Prowazek, and this is 
the only difference between my flagellate and such forms as figured by 
him. When house-flies in which active multiplication is in progress are 
examined, forms with a single flagellum may never be found and this is 
dependent upon a precocious flagellum formation, each flagellate being 
as it were in a hurry to have the new flagellum ready for a succeeding 
division. The result of this is that all the flagellates have either two or 
more flagella. A flagellate which has just resulted from longitudinal 
division has already two flagella arranged as shown in fig. 17. The 
kinetonucleus is an oval body limited apparently by a membrane. It 
