At the termination of the ileum the 'cæcum' makes its appearance, with a kind of valvular opening into it, of such a nature that everything that passes along it having reached the blind or closed end, must return in order to escape; or rather the office of the cæcum is to permit certain alimentary matters and all fluids to pass from the ileum, but to oppose their return. The 'colon' is an intestine of very large size, being one of the most capacious, as well as one of the longest, of the large intestines. It commences at the cæsum caput coli, and soon expands into a cavity of greater dimensions than even that of the stomach itself. Having attained this singular bulk, it begins to contract, and continues to do so during its course round the cæcum, until it has completed its second flexure, where it grows so small as scarcely to exceed in calibre one of the small intestines; and though, from about the middle of this turn, it again swells out by degrees, it never afterwards acquires its former capaciousness; indeed, previously to its junction with the rectum, it once more materially differs in size. At the upper part of the margin of the pelvis the colon terminates in the 'rectum', which differs from the cæcum and colon by possessing only a partial peritoneal covering, and being destitute of bands and cells. It enlarges towards its posterior extremity, and is furnished with a circular muscle, the sphincter ani, adapted to preserve the anus closed, and to retain the fæculent matter until so much of it is accumulated in the rectum as to excite a desire to discharge it. TETANUS, a disease of great fatality, often depends upon the condition of the stomach; but it is not frequent in dogs. Why the dog is so little subject to 'tetanus', or lock-jaw, I am unable to explain. Sportsmen say that it sometimes attacks him when, being heated in the chase, he plunges into the water after the stag. The French give it the name of 'mal de cerf', from stags being supposed to be attacked in a similar way, and from the same cause. In the course of nearly forty years' practice, I have seen but four cases of it. The first arose from a wound in the foot. The cause of the second I could not learn. In both the spasmodic action was dreadful as well as universal. The dogs lay on their sides, the neck and legs stretched out, and the upper legs kept some inches from the ground by the intensity of the spasm. They might be taken up by either leg, and not a portion of the frame change its direction. At the same time, in their countenances, and by their hoarse cries, they indicated the torture which they endured.