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Show MR. F. E. BEDDARD ON THE VASCULAR AND [M a y 1, thread lying on the ventral surface of the body-wall. It did not extend for a great distance, but was visible for four inches or so down the body. It did not join any of the veins putting the epigastric into communication with the portal system within the liver. It was quite clear from dissection that such of these veins as occurred in its neighbourhood crossed it without forming a junction with it. These various facts leave little doubt in my mind that this vein is the persistent umbilical, which is longer than in Python, and more like that of Eunectes for this reason. Text-fig. 91. Umbilical veins of (a) JBoa and (b) Python regius. ep. Epigastric veins ; L. Liver; wnb. Umbilical vein; Vci. Post-caval vein. The umbilical vein in Boa constrictor offers some interesting variations from the condition found in Boa, diviniloqua, though I do not assert for the present that they are actually specific variations. In the example which I dissected, the vein was longer than in the last species, and also vascular for a greater extent, thus resembling the Anaconda. Its relations to the postcaval vein were, however, quite as in Boa diviniloqua. The vein is as usual attached to the ventral surface of the liver, and it extended down to about the middle of that organ. A careful examination of the vein showed that it gave off, or rather received, a number of subsidiary trunks of very small calibre. These branches run over the liver, but they do not appear to form any part of the portal system. They are, in fact, so far as I could make out, distributed |