As it passed up along the left side, the gut caught hold of the left water-sac and pulled it upwards, curving it in the process; this being attached to the left duct from the anterior body-cavity, this structure with its water-pore was also pulled up, and the pore came to lie between mouth and anus.
- As already mentioned, mammals are specially characterized by the division of the body-cavity into two main chambers, by means of the horizontal muscular partition known as the diaphragm, which is perforated by the great blood-vessels and the alimentary tube.
It loses many of its larval organs, cilia, takes in a quantity of water into its body-cavity, sinks to the bottom of the sea, and begins life in its final form.
The defect of mouth-organs probably does not apply to the period of youth, which some of them spend parasitically in the body-cavity of worms (Giard, 1896).
An oblique septum which follows the bases of the tentacles and corresponds with that of the adult animal divides the body-cavity into two portions.
Body-wall not calcified, body-cavity absent.
These spaces make up the apparent body-cavity, the ta, Stomach of common crab, true body-cavity or coelom having Cancer pagurus, laid open, been, for the most part, obliter showing b, b, b, some of the ated by the great expansion of calcareous plates inserted in the blood-containing spaces.
These are suspended to the muscular bodywall by a double membrane, called the ligamentum denticulatum, which forms at once the roof of the atrial chamber and the floor of a persistent portion of the original body-cavity or coelom (the dorsal coelomic canal on each side of the pharynx).
The mouth does not open directly into the general cavity of the body, as is the case in a hydrozoan polyp, but into a short tube called the stomodaeum, which in its turn opens below ` into the general body-cavity or coelenteron.
The latter are almost invariably swallowed by their host in an immature state with its food, and from the stomach or intestine they work their way into the lungs, liver, body-cavity or blood vessels.