Section 16. Figure 1 Represents the General Anatomy of the Rabbit,

but is especially intended to show the alimentary (= food) canal, shortened to a certain extent, and with the proportions altered, in order to avoid any confusing complications. It is evidently simply a coiled tube-- coiled for the sake of packing-- with occasional dilatations, and with one side-shunt, the caecum (cae.), into which the food enters, and is returned to the main line, after probably absorbent action, imperfectly understood at present. A spiral fold in this cul-de-sac {bottom-of-sack}, which is marked externally by constrictions, has a directive influence on the circulation of its contents. The student should sketch Figure 1 once or twice, and make himself familiar with the order and names of the parts before proceeding. We have, in succession, the mouth (M.), separated from the nasal passage (Na.) above the palate; the pharynx (ph.), where the right and left nasal passages open by the posterior nares into the mouth; the oesophagus (oes.); the bag-like stomach, its left (Section 6) end being called the cardiac (cd.st.), and its right the pyloric end (py.); the U-shaped duodenum (ddnm.) and the very long and greatly coiled ileum (il.). The duodenum and ileum together form the small intestine; and the ileum is dilated at its distal end into a thick-walled sacculus rotundus (s.r.), beyond which point comes the large intestine. The colon (co.) and rectum (r.) continue the main line of the alimentary canal; but, at the beginning of the large intestine, there is also inserted a great side-shunt, the caecum (cae.), ending blindly in a fleshy vermiform appendix (v.ap.). The figure will indicate how the parts are related better than any verbal description can. Between the coiling alimentary tube and the body walls is a space, into which the student cuts when he begins dissecting; this is the peritoneal cavity (pt.). A thin, transparent membrane, the mesentery, holds the intestines in place, and binds them to the dorsal wall of this peritoneal space.