OVARY AND OVARIAN EGG OF ANOPHELES 44] 
a large part, of the follicles of an ovary have never been found 
affected, suggests that the phenomenon should be considered 
as one of atrophy or auto-digestion rather than as a disease. 
When an ovary is developing the follicles are very crowded 
and are obviously under compression, and it is probable, 
therefore, that the removal of several of the follicles from the 
more crowded parts would benefit the remainder. This may 
account for the degenerating follicles, but there is nothing but 
the above consideration to support the theory. 
Fig. 33 shows part of the degenerating epithelium of a follicle 
which has just commenced to produce yolk. It will be noticed 
that the appearance of degeneration is confined to the epithe- 
hum. This is normally the case, and it is only after the 
epithelium has almost broken down that the central mass of 
cells degenerates. Each epithelial cell produces one or more 
large globular masses inside the inwardly-directed portion of 
its cytoplasm, so that it closely resembles a goblet cell. The 
masses are very variable in appearance as they stain very 
irregularly. They are commonly very granular but are other- 
wise structureless. The thin protoplasmic investment of the 
globules soon breaks down, so that the globules form a mass — 
which penetrates amongst the nurse-cells. 
The mass of cells and globules appears gradually to enter into 
solution, as it decreases in size till nothing but a few degenerat- 
ing nuclei and a very loose tunica propria remain to indicate 
the position of the original follicle (fig. 24). 
PRESENCE OF SPOROZOA AND BaAcTERIA IN EGG-FOLLICLES. 
_ As has already been observed by 8. R. Christophers (2), the 
yolk of a mosquito egg is frequently entirely displaced by 
a mass of sporozoa. These appear as transparent spherical 
cysts 0-005mm. in diameter, approximating in size to the 
coarse yolk granules, in which eight small bodies which take 
up stain are found (fig. 10). In sections this number is not 
constant, but there are never more, and the reduced number 
is probably due to the removal of part of the cyst. This is the 
