A STUDY OF BLOOD MANUFACTURE 



113 



terior to the pharynx is the gullet ; it extends from about 

 the sixth to the fifteenth joint of the body, and there opens 

 into a thin-walled enlargement of the alimentary canal 

 called the crop. From this storage sac the food mass is 

 passed on into a muscular gizzard, where it is rolled about 

 and ground to prepare it for digestion. The remainder of 

 the food canal, 

 the stomach intes- 

 tine) extends from 

 the nineteenth 

 joint to the end 

 of the body. Here 

 the food is di- 

 gested and ab- 

 sorbed, 



The Alimentary 



Canal Of the Frog. FIG. 39. Internal Organs of the Frog. 



In the frog we 

 fin d a more highly 

 developed alimen- 

 tary canal than 

 that just de- 

 scribed. Seven 

 openings com- 

 municate with the 

 mouth cavity, cor- 

 responding in 



function to the seven in the throat of man. These open 

 ings are as follows: two from the nostrils, the mouth 

 opening, two communicating with the ear cavities through 

 the Eustachian tubes, the opening into the gullet, and 

 the glottis (opening into the larynx). The frog, there- 

 fore, has no distinct throat cavity. A short gullet conducts 

 the food into the cylindrical stomach, and a somewhat 

 coiled intestine communicates with the exterior of the body 

 through the rectum. The frog has a well-developed liver, 



a = stomach. 

 6 = urinary bladder. 

 c = small intestine. 

 d = large intestine. 

 e liver. 

 /=bile duct. 

 g = gall bladder. 

 h = spleen. 

 i = lung. 

 k = larynx. 

 I = fat body. 

 m = spermary. 

 n = ureter. 



o = kidney. 

 p = pancreas. 

 r = pelvic girdle. * 

 s = cerebral 



hemisphere. 

 sp = spinal cord. 

 t = tongue. 

 u auricle. 

 v = ventricle. 

 w = optic lobe. 

 x = cerebellum. 

 y = Eustachian recess. 

 z = nasal sacs. 



