THE SPERMATHECA OF EURYCEA BISLINEATA. 251 



I. 



THE MATURE SPERMATHECA. 



The spermatheca of Eurycea bislineata is a compact, definitely 

 bounded organ. Lying in a median dorsal position with reference 

 to the cloaca it extends from the opening of the organ, a point 

 cephalad to the vent of the cloaca, to the posterior wall which 

 lies above the vent of the cloaca. A mature spermatheca is 

 usually from 1/2 mm. to 2/3 mm. in antero-posterior extent, 

 approximately as wide as it is long and slightly higher, dorso- 

 ventrally, than it is wide that is, somewhat conical in shape. 



The spermatheca is a sac of tubules. The storage tubules, 

 where the spermatozoa lie in season, are flask-shaped, from seven 

 or eight to sixteen in number, and they converge into one central 

 tubule which bends abruptly and opens into the cloaca. The 

 sac is of heavily pigmented connective tissue. In the posterior 

 wall and the floor of the sac this is thickest, most coarse and 

 black, and the flask ends of the tubules are imbedded in the 

 mass as in sockets. The coarse, pigmented tissue thins out in 

 the anterior region and there is none of it in proximity to the 

 necks of the flask-shaped tubules or the central tubule. 



The extreme caudal end of the sac is but loosely connected 

 with the cloacal wall and surrounding tissues, being held in 

 place by scattered coarse strands of connective tissue. But 

 approaching the mouth of the organ, where the pigmented floor 

 thins out, it becomes more a part of the cloacal structure, the 

 smooth musculature of the cloacal walls merging with the similar 

 fibers of the interior of the spermatheca. 



The arrangement of the tubules is noteworthy. The flask- 

 shaped ends lie in the floor of the sac imbedded in pigmented 

 tissue. Some are quite anterior, being anterior to the plane of 

 the opening of the central tubule into the cloaca. But these 

 most anterior tubules, one on each side of the median line, have 

 their sockets of pigmented tissue though pigment is otherwise 

 sparse in this region. The necks of the flasks converge in the 

 posterior end of the sac and form the central tubule which runs 

 dorsally anterior. Thus some of the flasks have very long and 

 narrow necks. The convergence of the necks occasions a large 

 reservoir which narrows into the central tubule proper. 



