1870.] ANATOMY OF CHAUNA DERBIANA. 191 



narrow zonary belt of glands. It can, however, be seen that by far 

 the majority of the glands are aggregated into a posteriorly situated 

 patch. The only birds with which I am acquainted in which the 

 proventricular glands do not form a zone, or an approach to one, are 

 Struthio and Rhea. In the Galliuse and Anseres they form a zone. 



The glandular surface occupies a subelliptical space, 2 inches by 

 1 1 in its long and short diameters, in the upper and back part of 

 the canal, with the long axis in the direction of the tube. Its lower 

 end is 2 J inches from the upper orifice of the gizzard. The gland- 

 tubes are simple, not racemose, and average 4- inch in length. The 

 remainder of the area of the proventriculus, about five sixths of it, is 

 covered with coarse and irregularly folded epithelium. 



The gizzard is constructed on the usual type ; it is decidedly 

 small in proportion to the size of the bird (in the Anseres it is as 

 conspicuously large), being much more elongate, narrow, and less 

 muscular than in grain-feeders. Longitudinal folds plicate the tritu- 

 rating surfaces, which are smooth in the Geese, Ducks, and Swans. 



The spleen is the size of a haricot bean, and of much the same 

 shape. Its position is in no way peculiar; but, as in all birds, being 

 placed above the gizzard, it tends to confirm the opinion that the 

 latter organ is only the representative of the pyloric end of the 

 stomach, the cardiac component of which is represented by the 

 proventriculus. 



The liver is composed of two simple rounded lobes, united bv a 

 narrow isthmus of hepatic tissue ; the lobes are of nearly equal 

 size ; and there is a fairly voluminous gall-bladder. 



The following table gives the intestinal lengths : — 



Small intestine 



Large intestine 



Caeca 



The duodenum, with its characteristic bend round the pancreas, is 

 more capacious than the rest of the small intestine ; but it is not 

 large, being about \ inch in diameter. The hepatic and pancreatic 

 ducts enter it at the bend, 2| inches from the pylorus. 



The pair of cceca present a condition unlike that found in any 

 other bird with which I am acquainted. In that they are situated 

 some considerable distance from the cloaca, they agree only with 

 Struthio and Rhea. In the much larger Cassowaries the large in- 

 testine is not more than 7 inches long. In both Apteryx and the 

 Tinamous, as well as in all other birds, the Anseres and Gallinae 

 included, the large intestine does not exceed 4 inches in length. 

 Chauna in having a large intestine, the length of which is several 

 times the diameter of the gut, agrees therefore with St?'uthio and 

 Rhea only. These organs are figured in Plate XIII., they being 

 opened up in fig. 1 to show their internal structure. 



Instead of being smooth externally, the caeca are sacculated on 

 two longitudinal bands. They are peculiarly capacious for their 



