1896, ] INTESTINAL TRACT OF BIRDS. 149 
supplied by the posterior mesenteric vein. This structure is present 
in all the Accipitres I have examined, and Dr. Gadow states that 
all the Accipitres and Catharte have irregular kinks above the 
rectum. A similar deviation occurs in the Petrels (fig. 7, p. 143). 
GALLIFORMES. 
I have not had the opportunity of dissecting any Galliformes 
except Galli. The figure of the young Argus Pheasant (fig. 2) may 
serve as a type for the adult intestine of the Peacocks, Fowls, Quails, 
Tragopans, and so forth. The three great portions of the intes- 
tine and the three great mesenteric veins are always present in the 
typical form. The adult shows the vestige of the yolk-duct at the 
end of the middle mesenteric vein. Branches radiate off from the 
middle vein to the irregular loops of the circular fold, and the last 
part of the circular fold, along which the enormous cxea lie, is 
drained partly by a recurrent branch of the middle mesenteric vein 
and partly by short-circuiting branches from the vein of the duo- 
denum. The rectum is always straight. 
GRUIFORMES. 
Like the Galliformes, the Gruiformes closely conform to the 
primitive type. The gut is short, and instead of being thrown 
into a number of irregular minor loops the subsidiary loops are 
Fig. 13. 
Crex pratensis ; intestinal tract. , short-circuiting vessel divided. 
few in number and definitely placed. The Common Land-Rail 
(fig. 13) may be taken as typical of the Rallide. Porphryioand 
Aramides are practically identical with it, and the Cranes and 
Psophia differ only in minor particulars. The duodenum is a narrow 
regular loop: the circular loop is pulled out into four narrow sub- 
sidiary loops ; upon the distal limb of the second subsidiary loop the 
vestige of the yolk-duct is found. This is very large and is bound 
