29 
dad to enter the shell gland; the latter is immediately beneath (cau- 
dad of) the ovary. In the shell gland the oviduct unites with the 
vitelloduct. Just before entering the shell gland the oviduct receives 
Laurer's canal, from which point the latter passes centrodorsad to 
open in the median line on the dorsal surface about on the transverse 
plane of the termination of the intestinal ceca. 
From the ventral aspect of the shell gland and appearing like a 
continuation of a spindle shaped dilatation (ootyp) of the canal 
formed by the vitello- and oviduct there emerges the uterus which at 
once forms numerous coils. In its course cephalad the uterus passes 
dorsad of the testicles; a loop of it is tucked into the narrow inter- 
space between the two testicles. Cephalad of the anterior testicle it 
winds its way ventrad to the genital pore, passing caudad of the arch 
formed by the union of the two vasa efferentia, and remaining in 
close relation to the ventral aspect of the male canal. 
In its course the uterus contains numerous eggs and near its point 
of emergence from the shell gland some of the eggs ar^ intermingled 
with a mass of spermatozoa. 
The vitellogene glands lie in the lateral areas, beginning at the 
level of the esophageal fork and extending to a plane slightly caudad 
of the ovary. These vitellaria are composed of scattered irregiilarly 
globular follicles confined to the inner half of these areas. Some- 
what above (cephalad of) the level of the ovary the main right and 
left vitelloducts originate and pass mediad and slightly caudad in 
front (ventrally) of the intestinal tubes, to unite and form a common 
duct which curves around the caudal aspect of the shell gland, which 
it pierces to unite with the oviduct. 
Genital yore . — The genital pore is situated at a point about midway 
from the oral margin to the esophageal fork, namely, about one-ninth 
to one-seventh of the body length from the oral margin. It is at the 
summit of a very peculiar genital papilla, which is easily subject to 
misinterpretation because of its different appearance in different 
specimens, due to the greater or less condition of extrusion or re- 
traction. Sections with fully extruded papilla (figs. 31 and 37) 
form the best basis for study. When fully extruded, this papilla 
resembles somewhat the human penis with its glans. There is a dis- 
tinctly swollen terminal portion O.I mm. in diameter, and 0.2 nmi. 
long: this is followed centripetally by a constricted peduncle about 
0.25 mm. in diameter and 0.15 mm. in length; its surface is smooth. 
At its vertex is situated the genital pore (opening of the ductus her- 
maphroditicus) from which the genital canals lead centripetally 
in quite a direct course. The parenchyma of this papilla is composed 
chiefly of very striking, large cells, provided with disproportionately 
small nuclei. 
