20 SALT-WATER FISHES 



that the fact of congers refiasing stale pilchard is due to the 



acute smelling powers with which we know that fish to be 



endowed ; but some allowance should also be made for the 



peculiar medium in which fishes pass their existence. It is, in 



fact, not improbable that, although the nose may perform its 



share in apprising the conger of its want of freshness in the 



bait, oily particles may also float through the water in such 



manner that the conger, approaching close enough, could taste 



as well as smell any imperfection. 



The ear of fishes in not an ear at all perhaps, strictly 



speaking, in our restricted sense of the word. At any rate, it 



_ is not visible without dissection. Within the skull. 



The Ear. , , ...... I 



however, there are distinct and sensitive organs or 



hearing, together with small bones known as " otoliths," or 

 ear-stones.* These may be found without much difficulty in 

 the head ot any cod or haddock brought to table. These 

 internal ears are separated from the brain of the fish by 

 only a thin wall of membrane or cartilage, so that sound-waves 

 must be conveyed with great distinctness. It is, moreover, 

 probable that fishes are provided with what we may virtually 

 regard as supplementary hearing organs in the air-bladder, as 

 well as in the nerve-centres of the lateral line, but these are 

 distinct from, and auxiliary to, the ear proper. 



The mouth of fishes varies in size and position, as exempli- 

 fied in the sole [Solea) and angler-fish {Lophius), the weever 

 (Trac/iifjus) and skate {Raia), the gurnard (Trig/a) 

 'and gar-fish (Belone). The lips are very fleshy in the 

 wrasse [Lairus), and comparatively small in the bellows-fish 

 (Centriscus). The tongue, which fishes are not able to thrust 

 outside their mouth, like the higher vertebrates do, is in many 

 cases armed with sharp and numerous teeth, and may not 

 perhaps be endowed with any very sensitive powers of taste. 

 Some fishes, indeed, are without tongue altogether. 



* See Ridewood, " The Air-bladder and Ear of British Clupeoid 

 Fishes" {Joum. Anat. and Physiol. , Vol. XXVI., pp. 26-42). 



