50 COMPARATIVE ANATOMY. 



it is placed more anteriorly. Intestine spiral as in Mustela 

 (dogfish), convoluted, as in Zygoma (hammer-beaded shark); 

 terminates in anus without colon or caecum. Liver large, 

 oily, soft, lobular; gall-bladder present; duct terminates in 

 duodenum near pylorus. 



Pyloric caeca to stomach, as in Gadus (cod), furnish a pan- 

 creatic secretion. 



Batrachia. Tongue broad, flat, and attached anteriorly 

 to margin of lower jaw, with free part lying behind; gullet 

 short; stomach simple and intestine but little convoluted ; 

 rectum terminating in cloaca. In tadpole the intestine is 

 longer and more convoluted than in frog. Liver with gall- 

 bladder; salivary glands often wanting; pancreas present. 



Reptilia. Tongue of various forms. In Chelonia covered 

 with papillae ; long, slender, and protrusile in Chameleo (cha- 

 meleon). Gullet long, without crop. In Chelonia, furnished 

 with papillae or horny processes. In Ophidia, sometimes more 

 capacious than stomach. Stomach simple. In Crocodilia, giz- 

 zard-like. In Ophidia the stomach is small, merging insen- 

 sibly into gullet. Generally possesses thick, muscular walls 

 with marked pyloric constriction. Intestine divisible into 

 large and small; frequently with plicated mucous membrane 

 as in Ophidia, thrown into zigzag folds as in Crocodilia; 

 caecum rarely present except in Sauria. It always terminates 

 in a cloaca. Liver divided into two or more lobes; gall-blad- 

 der present, either embedded in organ (Amphisbcena) or remote 

 from it (Ophidia) ; salivary and pancreatic glands generally 

 present. 



Aves. Oral pouches in Pdicanus (pelican); oesophageal in 

 Otis (bustard). Crop (ingluvies) usually on right side of neck 

 in front of clavicles (furcula); in Columba (pigeon), one on 

 either side, and is often furnished with numerous and varied 

 glands. Power of regurgitation of the contents of crop pos- 

 sessed by some birds, as Columba. Crop absent in Anser 

 (goose), and Cygnus (swan). Stomach divided into two parts. 

 First, cardiac or glandular (proventriculus). This furnishes 

 the true gastric secretion; its glands are of a variety of shapes. 

 Second, pyloric, muscular (gigerium, gizzard). The walls are 



