4. THE LARVAE
105
consists of a forward part lying against the posterior regions of the
hepatopancreas, and of two limbs lying against each other which extend
from this forward part posteriorly under the heart and pericardium into
the first abdominal segment, so that the ovary is in fact a narrow horseshoe. The eggs grow in size in the follicles and are moved to the ventral
ov
\
sgl
t h
ov
od
sgl
ov
I
/
c
FIQ. 37. The female reproductive system of Euphausia superba when about half mature.
od, oviduct ; ov, ovary ; sgl, shell glands ; sp, spermatophore ; th, thelycum (exopodite
of sixth thoracic leg partly removed to show thelycum). (After Bargmann, 1937.)
side of the ovary so that those ready for laying are found immediately
above the germinal sites where the paired oviducts originate. At this
stage each egg lies in a separate follicle of epithelium, unlike the earlier
stages which occur in groups in a follicle. The eggs are tightly packed
within the ovary so that they are compressed into hexagonal, pentagonal, or conical shapes. After the initial increase in size of the ovary,
the rate of release of new eggs from the germinal sites decreases and the