ALIMENTARY TRACT OF CERTAIX BIRDS. 



73 



clown the duoilenal loop, but it is longer than in tlie Accipitres. 

 This fact, indeed, and the rather greater extension of the 

 ligamentum ileo-duodenale, is the chief difference that distin- 

 guishes the Owls from the Accipitres, the general plan of the gut 

 in these two subdivisions of birds being otherwise similar in many 

 ways. 



The groups that have been hitherto considered, viz. the Ratitfe, 

 Galli, Hemipodii, Picopasseres, Ouculi, Musophagi, Accipitres, and 

 Striges, agree with each other in that the jejunal region of the gut, 

 though it may vary gi'eatly in length, is never thrown into much 

 marked fixed loops, such as those which charactei-ise the groups of 

 birds that remain to be dealt with. There is, indeed, the commence- 

 ment of the formation of such loops to be seen in the Accipitres 

 and Striges ; but they do not arrive at the perfection and com- 

 plexity of interconnection which is exhibited in the i-emaining 

 families of Birds. Among the latter, however, with which I shall 

 proceed immediately to deal, there are species and even genera 

 which show the simpler conditions of the jejunum that characterise 

 the families of Birds already dealt with — for instance, in Phcvianus 

 among the Limicolae and in the Bustards and Cariamida?. In the 

 latter the simple conditions look like reduction ; while in Pluvianus 

 we may have to deal with an archaic representative of its family 

 which has not yet cast off the comparatively primitive type of 

 gut. 



Alectorides. — The Bustards are an example of a well-marked 

 family of birds which show a great uniformity in their intestinal 

 tract. The species which I have myself examined are Eupodotis 

 australis and Houhara macqueeni, and they evidently agree with 

 Otis tarda as described by Mitchell *. In Houbara macqueeni the 

 duodenal loop is attached to the ileic by a ligament which extends 

 to the very end of the former ; the ileic loop is considerably 

 longer than the duodenal. The pancreas extends as far as the 

 very end of the duodenal loop. The jejunal region is formed of a 

 single fixed loop, which is not quite so narrow as is depicted in 

 Otis tarda. Eiqjodotis australis (see text-fig. 23) has an intestine 

 which is so like that of Houbara that I can find no fresh terms in 

 which to describe it. Of birds admitted to be possibly allied to the 

 Bustards, that which most closely resembles the two genera just 

 referred to is Chunga hurmeisteri. The resemblance, howevei-, 

 does not quite reach, though it> very nearly approaches, identity. 

 In this bird the duodenal loop is, as in the Bustards, shorter than 

 the ileic. But the ileo-duodenal ligament stops about halfway 

 along the duodenal loop, though extending further along the ileic. 

 A point of likeness to the Bustards is the extension of the 

 pancreas to the end of the duodenal loop. The jejunal region of 

 the gut is also like that of the Bustards, in that it consists of but 

 one loop which occupies the whole region, of which, in fact, this 

 section of the intestine solely consists. Here we have an obvious 



* Trans. Linn. 8oc. t. c. p. 226, fig. 45. 



