20 THE ANGLER-NATUEALIST. 



chambers, and a few of three. Swimming-bladders are 

 more general amongst fresh- than amongst salt-water fish. 

 The whole subject is still, however, involved in con- 

 siderable obscurity; but an interesting chapter upon it 

 will be found in Mr. YarrelPs work on British Fishes *. 

 The annexed woodcut exhibits a section of the air-bladder 

 of the common Carp, with a probe introduced between the 

 two chambers. 



Sexual Distinctions. 



If we omit one or two species, there are no very obvious 

 external signs by which the sexes of fish can be identified 

 (except when in spawn, as hereafter explained). The dis- 

 tinguishing peculiarities, however, which, with a little prac- 

 tice, will be found sufficient guides, are as follows : 



In the males, the respiratory organs, or gills, are larger 

 than in the females, and, on the other hand, the abdomen 

 or stomach is smaller. The males may therefore be known 

 from the females by their somewhat sharper or more 

 pointed muzzles, by the greater length of the gill-covers, 

 and by the body, from the back-fin downwards, being less 

 deep as compared with the whole length of the fish. 



* 3rd edit., vol. ii. 



