1896.] INTESTINAL TBAOT OF BIBDS. 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 Outliartte have irregular kinks above the 

 rectum. A similar deviation occurs in the Petrels (fig. 7, p. 143), 



GALIiIFOEMBa. 



I have not had the opportunity oE 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 throe 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 veiu to the irregular loops of the circular fold, and the last 

 part of the circular fold, along which the enormous cssca 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- 

 denura. The rectum is always straight. 



GniriroiiMBS. 



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 ; inteatiiial tract, x, short-circuiting vessel divided. 



few in number and definitely placed. The Common Land-Eail 

 (fig. 13) may be taken as typical of the llallidee. Porphryio axydi 

 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 



