Of the organs lying on the reflected mantle-skirt, that which in the natural state lay nearest to the vas deferens on the right side of the median line of the roof of the branchial chamber is the rectum i', ending in the anus a.
Each opens in a vas deferens which bears three diverticula or vesiculae seminales, and three pairs of cement glands also are found which pour their secretions through a duct into the vasa deferentia.
As the vas deferens approaches the prostate it enlarges and becomes slightly sacculated to act as a reservoir for the secretion of the testis; this part is the ampulla (see fig.
The vas deferens descends with many undulations down the lateral side of the ureter of the same side, and opens upon a small papilla into the urodaeum.
To the right of the head is seen the muscular penis p, close to the termination of the vas deferens (spermatic duct) vd.
In the anterior part of the gland are seen bundles of striped muscle fibres, which are of interest when the comparative ana Ampulla of vas deferens tomy of the gland Cut end of great sacrois studied: they are 1 sciatic ligament Common ejaculatory duct Levator ani than in old prostates.