the passage or food pipe itself is tolerably regular in its shape. It proceeds along down. near the back bone till it has fairly passed the apartment of the chest, and enters the borders of the great apartment below it, occupying the second or lower story of the building. When it reaches the confines of this apartment, the passage enlarges into a spacious saloon. This is the stomach.

THE STOMACH.-The human stomach has some resemblance, in shape, to the bag of the Scottish instrument of music called the bag-pipe. It lies directly across the body, just under the edge of the ribs, and in such close contact with the diaphragm or floor of the apartment which contains the lungs, that the latter seem to rest directly upon it. The place where the food pipe enters is called the cardiac orifice, and the termination or outlet 1 of this spacious saloon is called the pylorus, or pyloric orifice. The meaning of the word cardiac is not of much consequence; the word pylorus will be explained hereafter.

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In this representation of the human stomach, the letter a represents the lower part of the gullet, or food pipe; c, the left or large extremity; d, the end or small extremity, and e, the pylorus. The stomach of an adult will hold, when moderately stretched, about two or three pints.

THE INTESTINES. These commence at the pyloric extremity of the stomach. They wind about in many and various directions, so that though it is scarcely more than a foot

from the place where they begin to the place where they end, their whole length is five or six times the height of the individual. Along with the stomach, they fill up almost the entire cavity or chamber of the abdomen. They are usually described in two divisions-the small and the large intestines.

The small intestines begin at the pylorus, as above mentioned. The first part of them is called the duodenum. This turns downward and backward from the pylorus towards the right side. There it makes another turn to the left, where it becomes the jejunum. This, after winding about in various directions, terminates in the ilium. The duodenum is comparatively short, perhaps not more than a foot or so in length: but the jejunum is longer. The ilium, however, is longer than all the rest of the intestines: in a person six feet high, it is probably more than twenty feet long.

At the lower end of the ilium come the large intestines. These, too, are generally described in three or four divisions or parts. The first of these is called the colon.

Just below the place where they unite, the intestine suddenly enlarges, so as to form a

kind of bag or purse, with its hollow part downward. This hollow part, or pouch, is called the cacum. Something in shape not unlike the finger of a glove, projects from it, of the length of three or four inches, but is closed at its lower end, so that nothing can pass through it. This is called the appendage of the cœcum.

The colon, continuing its course, first ascends upward on the right side, and crossing the abdomen just under the stomach, and over the duodenum, is called, as it crosses, the transverse arch of the colon. Then, turning a little backwards, it goes along down the left side, winding its way, in the shape of the letter S, till, coming near to the extremity of the body, it is called the rectum.

Lying in front of, and spread out over the intestines, and hanging, as it were, from the stomach, as may be seen at g, in the last engraving, is a fatty membrane, called the omentum, or caul. This membrane runs in among the smaller intestines, and seems to enclose them, as if they were wrapped up in it. Connected with it also are numerous little glands. They are called the glands of the mesentery.

THE GALL BLADDER.-Not far beyond the stomach is an opening or door, leading through a duct to the gall bladder and liver. The chambers of these two organs are little more spacious than those of the glands already spoken of which secrete the saliva. The gall bladder may be as large as a man's thumb, or sometimes larger. In the same neighborhood is the pancreas, or sweet bread, between which and the main passage through the body there is also a communication.

ABDOMEN.-In this lower story of the house I live in the abdomen-there are several other apartments besides those I have already described, some of which open externally, and others do not. But I must now describe another class of apartments-those which do not have communication with the air.

One of these has already been mentioned: it is the cavity of the chest. Another is the cavity of the cranium, or bones of the head. Another still is in the central part of the brain, or contents of the cranium. The last, but most curious and most important which I shall describe, is the great cavity of the circulation.