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Prof. W. Salensky on the 
and contains a somewhat sparsely developed network of 
chromatin-fibres. The expanded half of the kalymocyte con- 
sists of coarsely granular protoplasm, in which, even in 
freshly separated cells, one or two vacuoles are discernible. 
In the kalymocytes which have migrated into the segmen- 
tation-nucleus, the vacuoles increase in number as time 
goes on. 
Most of the kalymocytes immediately after their formation 
wander from their place of origin to different parts of the 
oosperm. Some enter the yolk, move about there, and reach 
the lower surface of the segmenting-nucleus ; the others 
wander into the space between the yolk and the follicle-wall, 
and finally arrive at the outer surface of the nucleus. Since 
the two kinds of cells differ materially from one another in 
form, I will deal with them separately. 
The migration of the kalymocytes into the yolk first begins 
at the time of the segmentation of the nucleus, and reaches 
its height at the period of the formation of the lower wall of 
the mesenteron. We can convince ourselves, by examination 
of successful sections, that immediately after the entrance of 
the kalymocytes into the yolk they undergo important changes 
in form, as well as in the constitution of their protoplasm. 
They assume an Amoeba-like shape and are much less readily 
stainable with carmine than the cells which lie on the wall of 
the follicle. The alteration in the extent to which they are 
affected by staining-reagents is probably due to the yolk 
which they absorb by the way. In consequence of the 
blanching of the protoplasm, the nuclei of the yolk-kalymo- 
cytes appear much more distinct than do those of the kalymo- 
cytes of the follicle- wall. The number of the kalymocytes 
found in the yolk is very variable in the different ova. Some- 
times we meet with a mass of star-shaped yolk-kalymocytes, 
which are united together in groups by their pseudopodia. 
The majority of the yolk-kalymocytes in their movements 
tend towards the upper pole of the oosperm, that is to say in 
the direction of the nucleus. We always find the largest 
numbers in the neighbourhood of the surface of the yolk on 
which the nucleus lies ; and since they invariably appear 
most numerous at the time of the development of the lower 
wall of the mesenteron, it is highly probable that they take 
part in the formation of the latter. This conclusion is sup- 
ported by the fact that, just at the point where the mesenteric 
wall is in process of formation, the kalymocytes can very fre- 
quently be observed emerging from the yolk. The liberated 
kalymocytes undergo a change in form, flatten themselves 
out, lose their pseudopodia, and range themselves alongside 
