546 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
section tlirough an ovary and also cuts a part of the oviduct (o). 
The ova in the sexual season are of all sizes, but the majority of 
them are very large and toward the center the largest ones are 
found entirely free and within the head of the oviduct. Around 
the periphery are considerable numbers of small nuclei {ctn)^ whose 
cytoplasm has apparently gone to form a syncytial framework which 
extends throughout the ovary and in which the ova are imbedded. 
There is nothing like a parovarium in the mature worm or at any 
stage which I have seen of the developing reproductive organs and 
the ovary is compact without irregular lobes extending into the 
parenchyma. 
The oviducts lead from the outer side of either ovary and extend 
posteriorly just above the nerve cord. Their walls consist of but a. 
single layer of cells. In some particularly good preparations I am 
quite sure that I have detected posteriorly directed cilia in the lumen. 
Back of the atrium the oviducts converge and mount to the dorsal 
side, and as they approach the midline, turn forward to unite as the 
common oviduct, the relation of which to the uterus and the vagina 
has been pointed out. « 
The mature yolk glands are connected with the oviduct every¬ 
where along its length. Only one kind of cell is to be found in the 
ripe yolk glands and these cells are loose in the cavity like so many 
enormous spermatids in a testis. The yolk glands extend every¬ 
where, tilling the space on the dorsal side and between the gut lobes 
so completely that there seems little room left for parenchyma. As 
they are kept out of the ventral region by the numerous testes, the 
result is that they are dorsally placed. They do not have any defi¬ 
nite position like the testes, which remain in that part of the paren¬ 
chyma where they first appear, but seem rather to have grown in 
and taken all the space that was left. Anteriorly they extend only 
a short distance in front of the ovary, but like the testes, extend 
back almost to the tail. 
/ 
The Degeneration of the Adult Reproductive Organs. 
After the egg laying, stages in the degeneration of the reproduc¬ 
tive organs may be readily found. The table shown below repre¬ 
sents these stages as I have found them. After knowing the devel¬ 
opment de 710V0 of the organs in small specimens, these stages will 
