400 ORGANS OF DIGESTION. 



(128. o. o. o.) and lined internally with a more or less dense 

 epithalium. This third cavity, the gizzard, lies in front of 

 the ovary (128. t. u. v.) and oviduct, (128. w. x. y. z.} in the 

 female, and of the testes in the male, and has its cardiac (c.) 

 and pyloric (e,) orifices closely approximated to each other. 

 The turns of the duodenum, (128. e.f. g.} on the right side 

 embrace the conglomerate and lobed pancreas, (128. q.q.) 

 which generally sends its secretion by two or more ducts, 

 (128. r.) alternating with the separate ducts from the liver 

 (128.0.0.0.), and the gall-bladder, (128. p.) The single, 

 lengthened, and dark coloured spleen, (seen above c. e,) is 

 attached near the left side of the glandular stomach, and the 

 divided liver (o.o.o.) has generally a free gall-bladder (128. p,) 

 placed under its right lobe. The intestine, (128. g. h. k.) 

 is still shorter than in mammalia, but its different divisions 

 are more distinctly marked than in the inferior classes. In 

 young birds a remnant of the original entrance of the yolk- 

 bag, or umbilical vesicle, is generally obvious in form of a 

 small co3cal appendage on the anterior portion of the small 

 intestine, and in many gallinaceous, wading, and water birds 

 it remains through life. At the commencement of the colon 

 (128. h. k,) which is here, as in lower oviparous vertebrata, 

 of short extent, and generally neither wide nor sacculated, 

 there are in most birds two coeca, (128. h. i. i. s. s.} of very 

 various lengths and dimensions, extending upwards, and at- 

 tached along the sides of the small intestine. The rectum, 

 (128. &,) terminates in the general cloaca (128. /,) which re- 

 ceives also the ends of the two ureters, the openings of the 

 pervious and impervious oviducts of the female, (128. z,) and 

 of the vasa deferentia of the male. 



The least constant of these digestive cavities, and the most 

 variable in form, is the crop or ingluvies, the caca-coli are 

 likewise inconstant and nearly as variable in their extent 

 of development and their form 5 the gizzard presents great 

 differences in the thickness of its muscular and cuticular 

 tunics, and the ventriculus succenturiatus in the development 

 of its glandular follicles. The crop, which is here remarkable 

 for its position in the neck, receives the unmasticated food, 

 like the paunch of ruminantia, or the cheek pouches of many 

 mammalia, and moistens it with the secretion of its numerous 

 follicles. It forms a large globular sac, communicating by a 



