CLASS OF FISHES. 343 



on the coast of Caflraria it is employed in fishing for other 

 fishes; a line being attached to its tail it is launched in 

 pursuit of others ; so soon as it becomes attached to them 

 the fisherman, by means of the string, gains possession 

 of both. 



484 The life of a fish is occupied almost wholly in pro- 

 viding for its subsistence and escaping its enemies; its senses 

 and faculties seem obtuse and limited ; it exercises no known 

 industry, and seems to be without any remarkable instinct ; 

 its brain is small, and the organs of sense imperfect. The 

 brain does not fill the cavity of the cranium, there being 

 found within it a spongy fatty mass, particularly in the adult 

 specimen. The lobes composing the brain are placed in a 

 file, one pair behind another, namely, the olfactory lobes, 

 the hemispheres, the optic lobes, and the little brain, and 

 behind that the lobes belonging to the medulla oblongata. 



Fig. 313. Remora. 



The sense of touch seems to be exercised only by their lips 

 and by the feelers surrounding the mouth (Fig. 306 b) ; their 

 taste must be imperfect, considering the structure of the 

 tongue ; and as the nasal fossae consist of cavities which are 

 traversed neither by air nor water mixed with air, the power 

 of smell cannot be acute. The organ of hearing is enclosed 

 within the cavity of the cranium, and is composed of a ves- 

 tibule and three semicircular canals, which sounds can only 

 reach by vibrations of the common integuments and bones of 

 the cranium. The eyes, it is true, are large, but not very 

 moveable, the iris is not contractile, and the lens is spherical; 

 they have neither eyelids nor lachrymal apparatus In some 

 flat fishes as the sole, plaice, turbot both eyes are placed on 

 one side of the head, and this want of symmetry extends to 

 other parts of the body. 



485. Fishes are very voracious: a very few only live 

 chiefly on vegetables; and they are indiscriminate as to their 



