FURTHER OBSERVATIONS ON CffflCAL PARASITES OF FOWLS. 67 
which is not fully understood, in which nearly all the 
chromatin is condensed on a large central karyosome. This 
form has been hitherto especially met with in recent infections. 
A slender axostyle is sometimes found in this form. 
Our series of divisions for this form is fairly complete, and 
we think that it shows clearly that in its early stages division 
may occur in any one of three planes. These divisions may 
be termed respectively longitudinal, transverse, and oblique. 
The determining factors between these three forms of division 
appear to be : (1) direction of division of the blepharoplast 
complex; and (2) direction of the outgrowth of the new 
chromatic line. In all three cases the first process consists 
in the separation of the basal granules forming the blepharo- 
plast into two moieties, each of which retains two of the 
original free flagella. The two new blepharoplasts arising in 
this way are connected by a darkly staining chromatic band. 1 
One of the new blepharoplasts retains its old position and its 
connection with the old chromatic line and the old membrane 
flagellum. The other new blepharoplast moves away in a 
direction which is either at right angles or parallel to the 
longitudinal axis of the animal. From this blepharoplast a 
new chromatic line quickly grows out, and it will be seen 
from PI. 11, figs. 15-30 more clearly than from any lengthy 
description that the initial plane of division depends largely 
upon the direction of the outgrowth of the new chromatic 
line. If, as in the cases PI. 11, figs. 15— 17, the line connecting 
the new blepharoplasts is at right angles to the longitudinal 
axis of the animal, and the new line grows out parallel to, 
and in the same direction as the old line, the division may be 
fairly described as longitudinal. If the line connecting the 
new blepharoplasts is parallel to the longitudinal axis of the 
animal’s body, and the new line grows out parallel to, but in 
the reverse sense to the old line, the initial stages of the 
division are transverse (PI. 11, figs. 18-24). If, finally, the 
1 This band has been regarded by other workers on similar forms as 
the axostyle. We can find no evidence for this view in this form, but 
we return to this point in our final summary. 
