Anatomical Observations on the Lungs

the lungs of smaller frogs are shaped; but in the larger ones, the walls are raised to a greater height, and from the middle of the contained area, three walls for the most part run out, increasing gradually, and meet one another. In smaller frogs, these walls are almost unobservable; but while they are joined to each other and to the larger walls, they divide the larger chamber into three other smaller chambers original: "sinus"; here referring to the pocket-like recesses or alveolar-like structures in the frog lung.. The floor or base of these chambers admits the vessels mentioned above. As for the artery, it sometimes does not end in a visible branch in the middle, but is extended further by its larger duct, and sometimes clearly puts forth one or two branches. The vein, however, glides along the internal summits of the walls and is mixed with them, and after sending branches down lower, finally runs out through the wall into the floor.

Once these things pertaining to the mere structure and composition were seen, a microscopic observation revealed more wonderful things. For while the heart is still beating, a contrary motion of the blood The "contrary motion" refers to the blood moving in opposite directions—outward through the arteries and back through the veins—confirming Harvey's theory of circulation. is observed in the vessels, though with difficulty, so that the circulation of the blood is evidently detected. This is even more successfully perceived in the mesenterya fold of membrane that attaches the intestines to the abdominal wall and holds them in place, rich in blood vessels. and in the other larger veins contained in the abdomen. Thus, the blood, by this impulse, passes through the arteries into each cell by one or another visible branch, or ending there, it flows down into the smallest parts in the manner of an overflow; and so, divided many times, it loses its red color and, guided around in a winding way, is scattered everywhere until it reaches the walls, angles, and the resorbing branches of the veins.

The sight of the eye could not be extended further in the living, opened animal; hence I had believed that the body of the blood broke out into an empty space, and was collected again by a gaping vessel and the structure of the walls. This idea was suggested by the tortuous motion of the blood, diffused in different directions, and its union at a determined part. However, my faith was made doubtful by the dried lung of a frog, which by chance had preserved the blood-redness in its smallest vessels (as was afterwards discovered). There, with a more perfect glass A reference to a high-quality magnifying lens or early microscope., the eyes no longer saw points forming a skin called Shagreen original: "Sagrino"; a type of rawhide with a rough, granular surface, often from shark or ray skin. Malpighi is describing the textured appearance of the lung tissue., but instead tiny vessels joined together in a ring-like fashion occurred; and