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Show 304 DR. H. G A D O W ON THE INTESTINAL [May 21, For much of the material, which comprises now far more than 300 species, belonging to nearly every principal family, including many of the rarest forms (such as Crypturi, Turnices, Pedionomus, Ocydromus, Opisthocomus, Rhinochetus, Podica, Trogon, Colius, Podargus, Manucodia, Pitta, &c), I am indebted to this Society, to its present Prosector, to Professor Newton, to the Museum of Cambridge, to that of the Royal College of Surgeons, the Natural History Museum at South Kensington, and last, not least, to my friend Professor Fuerbringer. Gifts from private hands, from ornithological friends, are remarkable for their scarcity ; those from Mr. Harvie Brown and from Sir Walter Buller were therefore all the more welcome. The intestinal canal, from the pylorus to the cloaca, is attached to the mesentery. This connects the folds or loops of the intestine with each other in various ways. In a typical loop we distinguish between a descending branch and an ascending branch ; both meet at the distal end or apex of the loop, and this of course forms its turning point. The starting point is the pylorus, the goal the cloaca. Each loop is either closed or open. It is closed when both the descending and the ascending branches are throughout the length of the loop closely bound together by an extension of the mesentery and its vessels. Of these vessels, as a rule, each principal loop receives one* bigger branch from the middle mesenteric artery. A loop is open when its two branches are not closely connected by mesentery and vessels ; the mesentery is wider, and the two branches of the loop can receive another loop or intestinal fold between them, the latter then resting upon the mesentery of the former open loop. The duodenum is always a typically closed loop. Its first or descending branch lies to the right of the second or ascending branch ; both invariably enclose the pancreas. A loop which runs in the same way as the duodenum may be termed right-handed; those loops which run in the opposite way are then left-handed, i. e. their ascending branch lies to the right, or ventral, of the ascending, or dorsal, branch. Again, if the intestine forms a number of (mostly closed) loops, which run parallel with each other in the long axis of the body, we term this arrangement orthoccelous, or straight-gutted. If, on the other hand, some of the loops form a spiral, we distinguish this formation as cycloccelous. Of the orthocoelous type the following modifications deserve especial remark with reference to the second and third loops; the first, or duodenal, loop is invariably right-handed, and therefore needs no further comment. I. Tsocoelous.-The 2nd and 3rd, and, if present, also the 4th loop are all closed and left-handed. The 2nd is most dorsally situated, the 3rd to the right of it, the 4th to the right of the latter, between it and the duodenum. The ascending branch of one loop runs side by side with the descending branch of the next following one. II. Anticcelous.-The 2nd and 3rd loops are closed and sharply attenuating ; the 2nd is left-, the 3rd is right-handed ; the 2nd lies |