| OCR Text |
Show 228 MR. F. E. BEDDARD ON THE [Feb. 4, At the posterior margin of the sternum the two oblique septa bend inward, and join each other in the middle, becoming here, as already mentioned, fused also with the umbilical ligament; anteriorly this roof formed by the oblique septa becomes continuous with the pericardium. The horizontally disposed roofing membrane formed by the union across the middle line of the two umbilical ligaments is, however, attached to the sternum on both sides for a short space by a membrane, somewhat slight and fenestrated (fig. 2, a, p. 227), which arises from the oblique septum just where it is bent over to assume a horizontal direction. The floor of the hepatic cavity of the right side, whose roof and sides are formed of body-wall, oblique septum, and falciform ligament, is a transparent membrane, anteriorly closely attached to the liver ; posteriorly it covers over body-cavity, being attached to oblique septum and to ventral parietes ; on the left side of the body it is continuous with the floor of the left hepatic cavity, which has corresponding attachments to the oblique septum and parietes of its o w n side : it splits so as to surround the gizzard. It is the " horizontal septum," " pseud-epiploon," or " so-called omentum." It follows, therefore, that each liver-lobe in Corvus capellanus is contained in a separate cavity, the two being divided by the umbilical ligament; each of these cavities is considerably larger than the liver-mass which it encloses, extending back nearly as far as to the cloaca. It is, however, to the relationship between the oblique septa and the falciform ligament that I desire particularly to call attention in the above description. I find that this peculiar arrangement of the oblique septa and the falciform ligament is not only characteristic of Corvus capellanus, but also of other Crows and of other Passerines. The Raven and the Alpine Chough agree absolutely with Corvus capellanus; so too Urocissa magnirostris, Paradisea minor, Pastor roseus, Starling, Gracula intermedia, Ptilonorhynchus violaceus, Vidua paradisea, Spanish Blue Magpie, Hyphantornis textcc, Leucodioptron canorum, Sturnella ludoviciana, Sialia wilsoni, Tardus merula, Pitangus sulphuratus, Furnarius sp., Tanagra striata, Cardinalis virginianus, Fringilla teydea, and a few others. In a specimen of the Rook (see fig. 3, p. 229) there is a slight difference, the oblique septa being split into two layers, one having the normal attachment, the other the Passerine. In Struthidea cinerea, again, I observed a slight difference in the arrangement of these various septa coupled with a general agreement. The point of difference was that, in the specimen of this bird which I dissected there was on each side a thin transparent partition arising from the falciform ligament and attached to the oblique septum of its side. This membranous partition did not, as it perhaps might have been expected to do, shut off the liver from the posterior portion of the abdominal cavity ; it arched over the liver with a semicircular free edge, one half of the liver being in front of it, the other behind. Leaving aside the characteristics of Struthidea for a moment, I desire to direct attention to the general feature of such Passerines |
