INTESTINAL TEACT OF BIRDS. 243 



. I have examined several specimens of Corythaix chlorochlamys and 

 C.persa, and have already figured the intestinal tract (26. fig. 20). The whole gut is 

 short and wide, in obvious association with frugivorous habit. This circumstance and 

 the fact that all the specimens I have seen were affected with tuberciilar nodules which 

 made the examination of the gut unsatisfactory, make it impossible to say anything very 

 definite regarding these forms. The duodenum is straight and of moderate width. 

 Meckel's tract appears in two portions, the proximal of which is a short, nearly circular 

 expanse on which there was no trace of a diverticulum, and the distal a supra-duodenal 

 loop very closely moulded on the duodenum and supplied by a large bridging vein. The 

 rectum was short and wide, and I found no trace of caaca. 



PSITTACI. 



TRICHOGLOSSIDUE : PSITTACID^;. Of the first family I have examined species of 

 Trichoglossus and Lorius ; of the second, species of Ara, Cacatua, Conurus, Chrysotis, 

 JEclectus, Palaornis, Psittacus, and Stringops ; but, as the conformation of the gut does 

 not differ in any appreciable fashion according to the families and subfamilies, I shall 

 treat them together. The larger forms have the gut relatively much longer than the 

 smaller forms, but, under the diversity so caused, the common type is apparent. In all, 

 the gut is very long and of small calibre ; the walls are thin, and the loops a,re folded 

 upon each other, and twisted and doubled in a complicated fashion. The masses of 

 twisted gut are bound together by connective tissue usually loaded with fat, and 

 "bridging" connections between the blood-vessels in adjoining loops are common. I 

 have already figured (26. fig. 21) the type as displayed in Ara ararauna. The duodenum 

 is long, narrow, and usually curved. Meckel's tract is drawn out into very long and 

 narrow loops, of which the last is always a long supra-duodenal loop with a " bridging " 

 vein. Of the others, three usually are apparent as in Trichoglossus, and any of these 

 three may become compound. Thus in Stringops (fig. 61), of the proximal loops 

 (marked " a " and " b " in the figure), " a " is expanded and shows traces of subdivision ; 

 " b " is subdivided into three ; " c" appears as two loops, one of which is further 

 subdivided, and only a comparison with other forms shows that the great length of the 

 tract has brought about this complexity. I am not confident about the position of 

 the diverticulum. In Ara there was present what I took to be a small representative 

 of it at the apex of loop " b" and in one other Parrot I have noted a similarly placed 

 trace. But in the others, including several other specimens of Ara ararauna, and in 

 other species of Ara there was no trace. The caaca always are absent, and the straight 

 rectum varies in length. 



The diet of the Cuculidse, consisting of insects, fruit, and flesh, is not of a nature to 

 have caused much homoplastic modification, and the conformation of the gut is such as 

 to make it possible to derive it from any fairly archecentric type. Garrod (13) and 

 others have suggested an affinity between the Cuculidae and the Galli, and, in so far as 

 the conformation of the gut in Galli is archecentric, there is nothing definitely against 

 such an origin of the Cuculine gut. On the other hand, there is nothing definitely in 

 its favour, for such apocentricity as is indicated in the gut of the Galli is different from 



