2. Villi of the Stomach and Intestines.—MM. Leuret and Lassaigne state that the villi can be easily injected; most conveniently from the vena portæ, though the arteries may be employed. In the latter case, the matter of injection is effused into the intestinal or gastric cavity. The villi are peculiar to these parts; they are inversely conical, adhering to the membrane by their smaller end. The best mode of exhibiting them, is to tie the vena portæ of a living animal, when they erect themselves by the afflux of blood. These diminutive organs, about 3/100 of an inch long, then exhibit distinctly, under the microscope, four red longitudinal lines, being probably vessels.
Injections made retrograde from the thoracic duct, pass through the villi into the intestines. When the stomach of a man, who died of some complaint not deranging its condition, is examined, we sometimes find its lining membrane covered with a multitude of minute white points. These are the villi in a flaccid state. In those who have died during digestion, they are erected, and of a rosy colour.
When the intestine of a living animal is examined under a microscope, after being carefully washed, a great number of orifices are seen, from each of which exudes a minute drop of a transparent fluid. These rapidly disappear; and then the villi attract attention. What these foraminula are, the reviewer, M. Du Fermon, does not tell us.—Ibid.
3. Minute distribution of the Vessels of the Liver.—M. Cruveilhier gives, in his lectures, an account of the results he has obtained from a minute injection of the liver. He finds, 1. The acini surrounded with a dense, cellular texture, paler than themselves; 2. The ramifications of the hepatic artery distributed to this cellular envelope; 3. Those of the vena portæ spread around the acini, or granulations of the liver; and 4. Those of the biliary ducts, and of the hepatic veins, emerging from the cavities of these bodies.
Our readers will observe a great similarity, in this, to the arrangement of the lobules of the kidneys.—Ibid.
4. Trachea perforating the Aorta.—This odd distribution of parts, was observed by M. Zagorsky, at St. Petersburg, in 1802. The aorta divided itself, at its arch, into two branches, which received the trachea between them, and again united, exactly fitting the organ they received. They were found to have compressed the trachea, and probably produced difficulty of breathing.
In another case, in 1808, the right subclavian artery, instead of its usual origin, arose from the left extremity of the arch of the aorta, and crossed behind the trachea, thus including the latter between it and the aorta.
Why do we call the common trunk of the right subclavian and carotid, the arteria innominata? Is coining words so difficult a task, that we cannot find a proper and expressive name for it? The French call it brachio-cephalic, and this expresses its office and distribution.—Ibid.
5. Monsters.—These productions, hitherto considered as mere objects of wonder, from the study of which no useful inference could be drawn, have recently attracted a good deal of attention in Paris. There seem to be some close affinities discoverable in many of them, not only with the natural and complete forms of animals of various tribes, but even with the actual condition of their own species, while in the fœtal state.
The views of M. Geoffroy St. Hilaire seem to us rather mystical and vague. Those of Breschet, and the other practical anatomists, we can understand much better.