DIGESTIVE ORGANS. 19 
[If the specimen be a female, remove the ovarres and ovuduects 
completely. | 
1. The Alimentary Canal. 
a, The esophagus: a short wide tube leading from the 
buccal cavity to 
b, The stomach: a wide tubular sac about an inch and a 
half in length: narrowed behind, and separated by 
a distinct pyloric constriction from the duodenum. 
Cut open the stomach longitudinally along its left hand edge: 
note the handle of the seeker already inserted through the mouth ; 
also the longitudinal folds of the mucous membrane lining the 
stomach, which serve to increase the extent of its surface. 
¢, The duodenum: the first part of the small intestine ; 
rather more than an inch in length: beyond the 
pylorus it is bent back so as to lie parallel to the 
stomach. At its further end it passes without any 
sharp boundary into 
d, The small intestine: a slender convoluted tube about 
four and a half inches long, opening at its distal end 
by a small orifice into 
e. The large intestine: a short straight tube about an 
inch and a quarter long: very much wider than the 
small intestine, and opening behind to the exterior at 
the cloacal aperture. 
f, The cloaca in the frog is the last half inch of the — 
— intestine into which open the renal and genital ducts 
as well as the bladder: it will be described more 
fully when considering the urinary and i Spee te 
organs. 
9. The Liver. 
A large reddish-brown organ, divided into right and left 
lobes, connected together by a narrow bridge of liver-tissue. 
Of the two lobes the left one is much the larger, and is again 
subdivided into two. 
a, The gall-bladder: a small spherical sac lying between 
the right and left lobes of the liver. 
& 
. 
