4io MANUAL OF ELEMENTARY ZOOLOGY 



The mouth has no teeth, no true palate (false roof) like 

 (pp. 394, 437) the rabbit's, large posterior nares 

 8yrtom l . ary partly hidden by soft palatal folds, a single open- 

 ing for the Eustachian tubes, and a sharp-pointed 

 tongue. The glottis is not protected by an epiglottis as 

 in the rabbit. The gullet widens into a thin-walled crop, in 

 which the food is stored. From the crop the canal continues 

 to the fore-stoh-ach or proventriculus, a glandular part of 



c. g. pr. 



Fig. 300. — The position of organs in a bird. — After Selenka. 



»., Nostrils; tr., trachea; cr., crop; h., heart ; st, sternum; pr., 

 proventriculus;^., gizzard; c, ca?ca ; /., pygostyle; pv., pelvic 

 girdle; k. , kidney; I;, lung. 



the stomach, where the gastric juice is secreted. This is 

 followed by the gizzard, a lens-shaped chamber with very 

 thick muscular walls and a horny lining, where the food is 

 ground up by the aid of small stones which have been 

 swallowed. It lies below the proventriculus, which opens 

 on its dorsal border, rather to the left side : on the right 

 side near the same spot is the opening of the duodenum. 

 This is a V-shaped loop, between whose limbs lies the 

 pancreas, The ducts of this gland are three, and all open 



