230 



COMPARATIVE ANATOMY. 



to a certain extent, the more one is developed, the less important 

 is the other. 



-a.b' 



st 



_,a.b 



9f.V 



FIG. 187. ALIMENTARY VISCERA AND AIR-BLADDER OF Lepidosteus, in situ. 

 (After Balfour and Parker.) 



a, anus ; a.b, air-bladder; a.b 1 , its aperture into the throat ; b.d 1 , aperture of bile- 

 duct into intestine ; c, pyloric caeca ; g. b, gall-bladder ; hp. d, hepatic duct ; Ir, 

 liver ; py, pyloric valve : s, spleen ; sp. v, spiral valve ; st, stomach. 



In the narrow-hodied Gynmophiona, the intestine is only 

 slightly coiled, while in Anura it becomes considerably folded 

 on itseJf. Its form in Salamanders is about mid- way between 

 these two extremes. 



