51 



tophores in the buccal pit consist of the sperm rope , enclosed in its membrane, 

 and the tlask , with a small portion of the neck and tube. The anterior end of 

 the rope is attached , pi'obably by means of a sticky substance upon the knob- 

 like process above mentioned , to the buccal membrane. The spermatozoa escape 

 graduall>" through {\u- tlask. The spermatophores taken from the penis usually 

 discharge and attach themselves to the walls of the mantle chamber, or to the 

 receptacle in which they are placed. By observing fresh spermatophores in a 

 watch glass , the discharge can be seen , but it is so rapid that one can only 

 record the result. The discharges obtained in this way , vary considerably and 

 ma\- not be normal. Usually the case breaks at or near the distal end and the 

 sperm rope with the flask apparatus escapes. The proximal end of the sperm 

 rope turns away from the case and fixes itself to a neighboring object, while 

 the flask tube remains attached for a time to the case. The expansion of the 

 spring is chiefly radial, serving to evert the filament so that the thickening 

 becomes external. The flask tube breaks not far from the flask and the sperm 

 escape as rapidly as they can free themselves from the rope. The use of the 

 filament and the complex telescoped tubes, and the stimulus which causes the 

 speraiatophore to discharge are unknown. The force necessary for the discharge 

 of the spermatophore is furnished by the elasticity of its capsule. 



B. The female reproductive system. 



The female organs of reproduction are the ovary, the oviduct with its 

 glandular portion , the oviducal gland , a pair of nidamental and of accessory 

 nidamental glands, and the buccal pit, or "copulatory pocket". 



The ovary , like the testis , is a median organ , but it is considerably larger 

 than the testis. Each ovum is carried in an oval follicle upon a slender stalk 

 formed mainly by the blood vessels of the follicle, and these stalks are clustered 

 upon the larger bloodvessels as grapes upon the stem. Bergmann has shown that 

 the ova of Cephalopods arise from cells of the coelomic epithelium , each of 

 which migrates into the underlying connective tissue , carrying with it one or 

 more epithelial cells which divide rapidly and form the follicular epithelium. 

 Each ovum increasing in size by growth and by the addition of yolk , is forced 

 out of the ovarian stroma into the coelom , and carries with it a peritoneal and 

 a connective tissue sheath. The blood vessels of the follicle form a complex 

 capillary network around the ovum and the larger vessels form ridges which 

 project into the surface of the ovum. The chorion appears first in the form of 

 isolated granules which finally unite to form a firm sheet. The micropyle lies 

 at the end of the ovum opposite the stalk and , as the connective tissue sheath 

 is much thinner around the micropyle, the free end of the ovum seems to 



