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Katharine Foot and E. C. Strobell 
terminal chamber of figure 1 was taken. In this ovary an egg chamber was formed 
in only two of the seven tubes. The delicate branches of tbe central canal are shown 
in zone B of this section the canal itself being demonstrated in the second section from 
the one shown in this sketch. See plioto 3. Fixative Hermann’s fluid. Stain iron 
haematoxylin. (See photo 1 for photograph of this section at the same magnification.) 
Fig. 3. + 1000. Section of a typical cell from zone B of a terminal chamber 
from anotlier tube of the same ovary from which figure 1 was drawn. Fixative, Flem- 
mtxg’s strong fluid. Stain iron haematoxylin. In this cell the nucleus is fragmenting 
into four pieces without a corresponding division of the cytoplasm. Photos 21 — 24 
show the same process in isolated nuclei. 
Plate XIII. 
Photo 1. The same section as fig. 2. + 180. 
Photo 2. + 283. A small area of the same section shown in fig. 2 and photo 1. 
This photo was taken to demonstrate that at the posterior limit of zone B the large 
nuclei of this zone change very suddenly into the small nuclei of zone C and that this 
change is largely due to fragmentation of the large nuclei. 
Photo 3. + 132. Part of a section of the same terminal chamber shown in 
photos 1 and 2 and fig. 2. This section demonstrates the central canal. It is the second 
section from the one shown in photos 1 and 2. 
Photo 4. + 155. Section througli two egg chambers one immature and the other 
nearly mature. The connection between the immature egg chamber and the central 
canal of zone B is not demonstrated in this section although it is present in other sec- 
tions of this ovary. This photograph was taken to demonstrate that the nearly mature 
egg chambers are still indirectly connected witli the central canal — the nearly mature 
egg chamber being in direct connection with the nutritive substance of the immature 
egg chamber which in its tum is fed by the central canal of zone B. The flow of the 
nutritive substance between the two egg chambers is somewhat deflected by a vacuole 
which is evidently an artefact. 
Plate XIV. 
Photos 5 — 10. Isolated nuclei from the posterior half of zone B. + 1000. 
The specimen from which these nuclei were taken was captured while mating and 
the ovaries removed at once. One or two egg chambers were developed in each tube, 
and each contained one egg, liaving the delicate blue tint characteristic of the 
immature egg. 
Photos 5 and 6 show quite typical resting nuclei with part of the chromatin se- 
gregated into a nucleolar structure. Photos 7 and 8 demonstrate a direct division 
of the large nuclei. Photos 9 and 10 show part of the chromatin segregated into a heavy 
coil. The chromatin of these coils apparently differs in no way from the chromatin 
which in photos 5 — 8 is segregated into a nucleolar-like structure. 
Plate XV. 
+ 1000 . 
Photos 11 and 12. Isolated nuclei from the posterior half of zone B. These 
nuclei are in the same area of the same ovary as those demonstrated in plate III. 
In the nucleus of photo 12 a group of pseudo-reduced chromosomes is seen. 
