304 DR. H. GADOW ON THE INTESTINAI. [Mav 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, Pediononms, 

 Ocydromus, Opisthocomus, Ehinochetus, Pudica, Trogon, Colius, 

 Podargus, Manncodia, 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 turn- 

 ing point. The starting point is the pylorus, the goal the cloaca. 

 Each loop is either closed or open. It is closed when both the de- 

 scending 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 rigJit-lianded ; those loops which run in the opposite way are 

 then left-handed, i. e. their ascending branch lies to the riglit, 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 

 orthoccehus, or straio-ht-gntted. 



If, on the other hand, some of the loops form a spiral, we dis- 

 tinguish this formation as cyclncoelous. 



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. Isocoelous. — Ihe 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. Anticoelous. — The 2nd and 3rd loops are closed and sharply 

 attenuating ; the 2nd is left-, the 3rd is right-handed ; the 2nd lies 



