Diverticula from the FIG.
In the majority of the Megascolicidae each sac is provided with one or more diverticula, tubular or oval in form, of a slightly different histological character in the lining epithelium, and in them is invariably lodged the sperm.
The oesophagus is often furnished with glandular diverticula, the "glands of Morren," which are often of complex structure through the folding of their walls.
The alimentary canal is simple and a gizzard or oesophageal diverticula rarely developed.
Spermatheca rarely with diverticula; sperm ducts as a rule occupying two segments only, usually opening by means of an atrium.
These diverticula extend usually one into each of the dorsal papillae or " cerata " when these are present.
The posterior portion of the intestine is specially characterized by the appearance of the intestinal diverticula horizontally and symmetrically placed right and left and opposite to each other.
As the animals become adult, diverticula arise on the tubes of these organs, which develop either spermatozoa or ova.
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.
There is further a great tendency for the endothelial cells to form muscles, and this is especially pronounced in the small arm-sinus, where a conspicuous muscle is built up. The mantle-sinuses which form the chief spaces in the mantle are diverticula of the main coelomic cavity.
The dorsal branch sends a blind twig into each of the diverticula of the dorsal mantle-sinus, the ventral branch supplies the nephridia and neighbouring parts before reaching the ventral lobe of the mantle.
The functions of these gastric diverticula have never been carefully investigated.
M, The Malpighian or renal caecal diverticula of Scorpio.
Ischio-rectal fossa Tuberosity of ischium Gluteus maximus The vesiculae seminales are sac-like diverticula, one on each side, from the lower part of the ampullae of the vasa deferentia.
The external duct of this gland is often dilated into a bladder, and may sometimes send out diverticula, forming a complex system of sinuses ramifying through the body.
The oviducts may have diverticula serving as receptacles for the spermatozoa (in cases where internal impregnation takes place), and may be provided with glands secreting envelopes or shells around the eggs.