364 
REPRODUCTIVE ORGANS — VAGINA AND EGERSIDIA. 
which it separates as the vagina, the sperm duct becoming the vas 
deferens. 
The Vagina (ir(g(na, a slieath) is the oviduct wlien freed from its 
adherence to the glandular sperm duct; it then becomes more 
muscular and contracted, and several auxiliary organs open into it, 
the uppermost being the vaginal glands ; these may exist as a dense 
investment surrounding the vagina, or in the more advanced forms 
take the shape of a variable number of digitate or finger-shaped 
tubes, which are usually paired and placed at either side of the 
vaginal tube. 
Tig. GGo. — P roximal portion of reproduc- 
tive organs of llyalinia ai/iaria (Sillier), 
X 6, showing the position and character of 
the vaginal glands. 
Fig. GG6. — Proximal portion of reproduc- 
tive organs of Helix y-^i/escens Penn,, X 6, 
showing the character and arrangement of 
the paired digitate vaginal glands. 
cn>, oviduct; 7'.gL vaginal glands; s.d. 
sperm duct ; XKd, vas deferens ; p.s. penis 
sheath ; sp. spermaiheca. 
v.gL vaginal glands ; v, vagina with dart 
sacs ; p s, penis sheath. 
The vaginal glands discharge directly into the vaginal tract, or in 
the case of the digitate glands may retain their secretions and dis- 
charge the secreted contents as recpiired. 
The Appendicula is an outgrowth of the female system, whose 
particular function is as yet unknown, but it has been assumed to act 
as a receptacle for spermatophores. 
The Egersidia (eyepo-ts, an exciting, an awakening) are possessed 
in various forms by widely different groups of mollusks and are 
special organs whose function is to stimulate or excite sexual passion 
or desire and thus include not only the fieshy “reizkorper” of the 
Lhnacidw and the fully calcareous or chitinous love-darts of the 
Helices and other genera, but any organ by whose actions amorous 
feelings are encouraged. 
Although so different in aspect and structure, the calcareous love- 
dart and tlie flesliy rei/.kiirper are eiiually and simply excitatory 
organs, and numerous intermediate forms exist linking them together, 
all subserving the same purpose of producing or increasing the amo- 
rous desire leading up to sexual congress, as the egersidia in their 
