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An examination into the caecal appendages, also termed 

 pyloric caeca, and pyloric appendages what forms possess, 

 and what are deficient in them under what circumstances 

 they vary and, lastly, what are their functions? have 

 always appeared to me to be questions respecting which 

 much still remains to be ascertained. One constantly sees 

 observations respecting these organs and their importance, 

 but one rarely finds remarks as to what role they subserve 

 in the economy of fishes. One author divides species by 

 the number of appendages they possess. Another tells us 

 that they may be considered as lateral prolongations of the 

 intestines, into which food does not enter, and the secretion 

 which comes from them is similar to that of the intestinal 

 mucous membrane. Some consider these appendages to 

 be a modified pancreas, while a very rudimentary form of 

 this organ has been detected as a minute glandular body, 

 terminating in a duct, which opens by from one to three 

 orifices into the intestines, close to the bile duct, but occa- 

 sionally so closely attached to the latter as to be easily 

 overlooked. It is seen both in fishes which possess pyloric 

 appendages, as perch, cod, salmon, sturgeon, and also in 

 such as are deficient in them, as brama, gar-pike, pike ; 

 while the sharks and rays are furnished with a reddish- 

 yellow and lobulated gland, which is more similar to what 

 is perceived in the higher forms of vertebrate animals. In 

 short, we may find both a true pancreatic gland and caecal 

 appendages existing in the same fish. 



What are the common appearances of ccecal appendages ? 

 If we commence our investigations among the osseous 

 fishes, we see in some one or more small ducts, each ending 

 externally in a blind extremity ; these either surround the 

 commencement of the intestine just beyond the pyloric or 

 lower end of the stomach, or else spring from one of the sides 



VOL. VI. C. T 



