248 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



The vaginal portion of the large hermaphrodite dnct lies 

 on the left of the dnct near the opening, the penis entering it 

 from the left during copulation. In its anterior portion the 

 walls are only slightly folded. It is connected with the lateral 

 pocket or bursa seminalis. The walls of the bursa are composed 

 of tubular glands (Fig. 20b, b. sem. gl.) which discharge into 

 the cavity of the bursa. The duct of the spermatheca (spth. d.) 

 enters the bursa anteriorly. The spermatheca (Swaimnerdam's 

 vesicle) is thin walled, and both vesicle and duct are ciliated 

 internally. The vesicle is rarely empty, but usually contains 

 a mass of waste matter agglutinated together by the secretion 

 from the glands of the bursa. The contents consist of effete 

 eggs, granules of yolk and albumen, and a few sperms. 



Just as the spermatic portion of the duct crosses from right 

 to left of the large hermaphrodite duct, so the vaginal or 

 copulatory portion crosses from the left to the ventral side. 

 It is difficult to trace the vaginal duct with accuracy by the 

 ordinary methods of dissection. The investigation was 

 carried out in the following way. The penis of an individual 

 acting as male was cut as close to its base as possible during 

 copulation. The " female " was then killed, and the repro- 

 ductive apparatus removed and sectioned with the penis still 

 within the vagina. It was found that the penis penetrated 

 much further into the large hermaphrodite duct than is usually 

 stated. Mazzarelli describes it as reaching to the level of 

 the bursa, and discharging its sperms in an impure condition 

 into the duct leading to the spermatheca. It was found, 

 however, that the tip of the penis was thrust into the vaginal 

 pocket (vag. p.) leading to the spermatocyst, i.e., almost to 

 the base of the large hermaphrodite duct. It was held in 

 place, not only by the folds separating the copulatory duct 

 from the sperm duct and oviduct, but by a double fold, 

 within the trough of which it lay, arising from the wall of the 

 copulatory duct. From the pocket a double fold runs into 



