Aristotle : On the parts of animals / translated, with introduction and notes by W. Ogle.
- Aristotle
- Date:
- 1882
Licence: Public Domain Mark
Credit: Aristotle : On the parts of animals / translated, with introduction and notes by W. Ogle. Source: Wellcome Collection.
246/316 page 198
![respectively. Any one who reads A.’s description will see that this view of the matter is utterly untenable, and would turn • every sentence in the description into nonsense. There can, I think, be no possible doubt that the three cavities are the right ventricle, the left ventricle, and the left auricle. Why it may be asked did A. omit the right auricle ? Simply because he looked on it as a venous sinus, being a part not of the heart but of the great vein {i.e. superior and inferior vena: cavoe). That he so regarded it, is plain from his always speaking of the superior and inferior vena: cavoe as forming a single vessel, not as two distinct ones, and he even says in one place (//. A. iii. 3, 8) that the heart Appears very much like a part of the great vein, being interposed between its upper and lower divisions. Galen held a precisely similar view of the right auricle. “ Galien,” says Daremberg (i. 387), “ considere la veine cave superieure comme une continuation directe de la veine cave inferieure, I’oreillette droite n’etant qu’un diverticulum ou un lieu de passage.” Such a view was q,uite natural; for the right auricle “ semble'formee par la reunion des veines caves qui s’ouvrent aux deux extremity superieure et inferieure de cette oreillette” (Cuvier, Lemons, iv. 199). This being understood, A.’s descripti&n of the heart becomes fairly intelligible. Here are the main |Jarts of it, as I interpret them. “ The heart has three cavities. The largest is placed on the right (right ventriele)-, the smallest on the left (left auricle')-, and the one of middle size (left ventricl^'Vies in the middle. All these cavities—even the two smaller ones—have openings in them which lead to the \mig(pulmo7iary artery; pulmonary veins ; and, for the.left ventricle, the foetal ductus arteriosus), but it is only in one of them (fight ventricle) that the communication with the lung is conspicuous (pulmonary artery). The largest cavity (right ventricle) is connected with the great blood-vessel ,(right auricle which, is simply dilated junction of ve?tce cava); and the middle cavity, (left venh-icle) *is connected with the aorta. Moreover passages (pulmonary artery and veins) lead from the heart to the lungs, and divide after the same pattern as the windpipe, their branches accompanying the branches of this latter throughout the whole lung, and the former being placed above the latter. There is no •communicating passage between these two systems of branches, but those which come from the heart receive the breath from the others, in consequence of their close contact with them,’and transmit it to the heart. For one of the passages (pulmonary artery) lends to the. right cavity (right ventricle) and the other (pulmonary veins) to the left cavity (left auricle) ” (H. A. i. 17). And agaih, “The heart in the largest animals has three-cavities. The. largest of these (fight ventricle) is on the right, and is above the rest; the smallest (left auricle) is on the left; and the middle one in size (left ventricle) is also the middle one in. position. Each of the two latter cavities is much smaller than the largest one (right veiitricle). All three have openings which lead to the lungs ; l^ut these openings are so small as to be scarcely visible, excepting in one cavity (right ventricle). The great blood-vessel (right auricle and vena: cava) is connected with the largest cavity (right ventricle), and after passing through the centre of the cavity issues from it again in the form of a blood-vessel (pulmonary artery), as though the qavity were a part of the vessel, in which the blood collected as in a reservoir. The ao.rta issues from the middle cavity (left ventricle), having however a much nanower tube [than the pulmonary artery’]. The great vessel (pence cava: plus right auricle) passes through the heart, and after issuing from it (as pulmonary arioy) extends into the aorta (by the ductus arteriosus). The great vessel is membranous and skin-like ; but the aorta, which is smaller than the great vessel, is very- • tendinous, and, as it extends upwards towards the head and .downwards towards the lower parts, gets narrower, and assumes altogether the character of sinew (cf. Note 20). The great vessel sends first a branch upwards above the he.arf, to the lung and the junction with the aorta (pulmonary artery and ductus arteriosus), this branch forming a](https://iiif.wellcomecollection.org/image/b24864249_0246.jp2/full/800%2C/0/default.jpg)
