654 DR. p. CHALMERS MITCHELL ON THE 



or on mixed diet have the miisculax portion nioi'e specialized and 

 a tendency to the concentration of the glands. Even a formation 

 so remaikable as the aggregation of the proventricular glands into 

 two large circular masses has apparently little or no systematic 

 significance. Within the groxip generally, the arrangement of 

 the proventricular glands is diffuse over the whole area, but 

 there is a tendency for them to lie in longitudinal bands, which 

 may be numerous, as for instance in the Sea-eagles and in 

 Balceniceps, or in two bands one anterior and one posterioi'. I 

 found these bands rather short and rounded ofl" in the American 

 Grebe {^Echmophorus major) and even more definitely rounded 

 off in Garden's Night- heron [Nycticorax gardeni). The condition 

 I described and figured for the African Tantalus (Fsettdoia'/italus 

 ibis), where the glands are in a couple of rounded bosses, and 

 which I noted as occui'ring also in Lej)toptilus crumeniferus and 

 L. argala, and in Carphibis spinicollis (25), is obviouslj^ a. simple 

 derivative from the pair of rounded bands. The state of affaii'S 

 noted by Garrod in Levaillant's Darter (20) and by Forbes in the 

 Indian Darter (11) differs from that in the Storks only by 

 the circular form of the two patches being a little more advanced 

 and by a slight tendency for the circular masses to retreat into 

 eversions of the stomach wall, a condition which is completed in 

 Plotus anhinga (19) by the two patches having retreated into 

 a rounded diverticulum. It is clear that the absence of sucli 

 circular patches in Bcdcenicejos tells us nothing as to the place of 

 that bird in the system. 



When I found that there was a well-marked pyloric chamber, 

 a fact which appears not to have been recorded before, I at once 

 remembered the existence of such a chamber in the Pelican from 

 my own notes, and in Plotus from the observations of Garrod and 

 Forbes. But as Leuckart (loc. cit.), Gadow (14), Cazin (6) and 

 many others have shown, a pyloric chamber in varying degrees 

 of completeness of separation occurs in many birds, notably in 

 Herons, Storks and Darters ; and even if Ave try to follow Cazin 

 in limiting the term to cases where the constriction from the 

 larger chamber is very well-marked, its presence gives no sure 

 ground for associa,ting Bcdceniceps more closely with any one of 

 the groups of allied birds. 



Liver. — As Beddard (3) has noted, the right lobe of the liver is 

 very much larger than the left, a condition which he was inclined 

 to think showed affinity with the Herons rather than with the 

 Storks. In a later work (4), however, he states that the " relative 

 sizes of the liver lobes appear to be of no importance syste- 

 matically" — an opinion with which I concur. There is a large 

 gall-bladder, and the cystic and hepatic ducts open nearly 

 together, but the cystic duct distad of the hepatic duct, just 

 beyond the end of the straight distal limb of the duodenal loop 

 of the intestines, the disposition being very like that figured by 

 Beddard in the case of the Indian Darter (4, p. 32) except that 

 the hepatic duct passes through the substance of the lobulated 



