1896.] INTESTINAL TRACT OF BIRDS. 148 
three parts. In Hudyptes chrysocome the duodenum forms a 
subsidiary system of loops ; in Aptenodytes pennanti a spiral, bearing 
a convergent resemblance to the duodenum of the long-gutted Sea- 
Eagles. The circular loop is thrown into an enormous series of 
minor folds, about the middle of which, but in a position similar 
to that in the Divers, occurs the yolk-duct vestige. The last two 
loops are supplied from the duodenal vessel. The posterior part 
of the gut is quite like that of the Diver, although the cca are 
still further reduced. 
PROCELLARIIFORMES. 
The Northern Petrel (fig. 7) presents several interesting modifi- 
cations of the type. The duodenum is compound, the first part 
being twisted round the small gizzard, the second part forming a 
Fulmarus glacitalis ; intestinal tract. 2, short-circuiting vessel cut across. 
long loop containing the pancreas in the typical fashion. The 
circular loop is drawn out into a number of straight narrow loops, 
on the fourth of which occurs the vestige of the yolk-duct. The 
last loop is drained partly from the normal source and partly by a 
short-circuiting vein from the duodenum. The posterior part of 
the intestine is like that of Colymbus and the Penguin, with the 
exception that, as in the Sea-Eagle, the portion of the gut supplied 
by the posterior mesenteric vessel, but anterior to the origin of the 
ceca, is expanded into two subsidiary loops. 
CICONIIFORMES, 
The birds in this group that I have examined have all departed 
similarly from the type. The whole intestine is enormously elon- 
