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of the first part of the small intestine, along which they may 

 be continued for some little distance. We find in a single 

 fish from one to upwards of a hundred of these caecal 

 appendages, each of which may open by a separate orifice 

 into the intestinal canal, or two or more conjoining form a 

 common duct, and thus diminish the number of openings. 

 In the sword-fish (Xipkias), all the various appendages 

 conjoin with the common tubes which empty their contents 

 into the intestines. Passing from the osseous upwards to 

 the cartilaginous, or semi-cartilaginous fishes of the ganoid 

 sub-class, we still find this gland present. Thus in the 

 sturgeon (Acipenser), a mass of areolar tissue binds the 

 various caeca together, forming it into a parenchymatous 

 conglomerate gland. 



Food, climate, and increased space of water, or all 

 combined, exercise a modifying influence upon the caecal 

 appendages of fish ; thus trout in Tasmania, reared from 

 eggs sent from Hampshire and Buckinghamshire, have 

 increased largely in size in their new home augmented the 

 number of their caecal appendages, and are now in most 

 respects identical in appearance with the Saimo ferox of 

 our larger lakes. 



Respecting our freshwater fishes, their food has been 

 more closely investigated than has that of our marine 

 forms, and, for very obvious reasons, the owner of a fishery, 

 if he takes any interest in its development and success, 

 watches whether his fishes thrive or deteriorate, and also 

 endeavours to ascertain to what cause such may be due. 

 Possibly his fish-ponds may be too full of small and inferior 

 kinds, which, by devouring the food; leave but an insufficient 

 supply to the more valuable table sorts. Possibly the food 

 itself is deficient in quantity or nourishment. But all 

 these questions fall so naturally to the freshwater fisheries, 



