N. H. SWELLENGRBBEL 
117 
In preparations stained with iron-haeinatoxylin these changes in the 
structure are very indistinct; Diagram VI (Fig. 3) shows that the 
figures are, in general outline, the same as after Giemsa’s stain. 
Diagram VI. 
Ilerpetomoiias calliphorae after fixation in corrosive-alcohol and staining with iron- 
haematoxylin. Fig. 3 shows a stage of division (V-shaped blepharoplast). 
2. Preflagellate stages. 
These are round cells measuring 7-10 g in length, and 6-9 /r in 
breadth (Diagram VII). They are to be found in the crop. The 
nucleus has sometimes a distinct achromatic karyosome staining blue 
with Giemsa’s solution. The blepharoplast is generally large, the 
fiagellum is either completely absent or a pink-staining rhizoplast, single 
or double (Figs. 1-3), may be seen near the blepharoplast; sometimes 
a distinct short flagellum is present (Figs. 6, 7). Division is common 
among the preflagellate stages as already pointed out by Patton 
(Figs. 3, 4). Fig. 4 shows stages of division of the nucleus and 
blepharoplast. The nuclear division is of the common pattern; the 
distribution of the chromatin in the dividing blepharoplast is rather 
irregular; in Fig. 4 it suggests a sort of mitotic spindle, but I presume 
it is only accidental and has no special significance. 
Large chromatoid granules, composed of volutin, are conspicuous in 
the preflagellate stages, and are much more numerous than in the 
8—2 
