ORGANS OF DIGESTION. 



401 



narrow neck with the fore part of the resophagus in most of 

 the gallinaceous birds, as represented in the annexed dia- 

 gram, (Fig. 129. A. b,} and in the pigeons it is still larger, 



FIG. 129. 



and divided in front into two lateral sacs. The numerous 

 follicles which open into its interior, become more vascular 

 and enlarged at the time these birds are rearing their young ; 

 the milky secretion which they afford is very abundant in the 

 crop of the pigeon, when feeding its young, and this is the only 

 food they receive for the first two or three days after being 

 hatched. The grains which have been moistened, softened, 

 and partially digested in the crop, are brought up successively 

 from that cavity and conveyed into the mouth of the young 

 birds when they are further advanced. In the diurnal rapa- 

 cious birds, (Fig. 129. B.) the crop (,) forms only a general 

 enlargement of the lower cervical portion of the O3sophagus, 

 into which entire prey is conveyed, and from which the hair, 



PART IV. D D 



