428 



ANATOMY OF VERTEBRATES. 



before it enters the commencement of the wide intestine, near the 

 beginning of the spiral valve. The gall-duct in the Sturgeon and 

 Planirostra terminates at a greater distance above the valvular 

 intestine. The ordinary position of the entry of the bile into the 

 alimentary canal in Osseous Fishes is at the commencement of the 

 small intestine near the pylorus. The terminal part of the gall- 

 duct is usually slightly expanded, fig. 291, e, and its orifice is often 

 supported on a papilla, as in the Sturgeon, the Skate, and the 

 Labrax lupus. 



§ 74. Pyloric Appendages and 



285 



Alimentary cimiil nf tl 

 siliowing Uir I'lle (if I'll 



Dermopteri sluiw 

 canal is simple : 



no 

 the 



trace 



Pancreas of Fishes. — In most 

 Osseous Fishes the intestine 

 buds out at its commencement 

 into long and slender pouches, 

 or ca3ca, fig. 281, d, into which 

 it ajjpears that the food does 

 not enter, and which, there- 

 fore, increase the direct secre- 

 ting surface of the alimentary 

 tract, over and above the ex- 

 tent of the mechanism for 

 pounding and propelling the 

 chyme, or of the vascular sur- 

 face which selects and absorbs 

 the chyle. By a very gradual 

 series of changes of these cascal 

 processes, within the limits of 

 tlie class of Fishes, they be- 

 come massed into a body, fig. 

 282, d, like the conglomerate 

 gland, called ' pancreas' in Man. 

 The secretion of the rudimen- 

 tal representatives of this gland 

 is so like the fluid which the 

 ordinary mucous surfiice of the 

 intestine eliminates and sets 

 free from its capillary system, 

 that conditions of the ordinary 

 alimentary tract exist in some 

 Fislies which render needless 



"■ the devclopemeut of the spe- 

 cial accessory surfaces. The 



pancreas ; their whole digestive 

 for which that canal is the 



