ICHTHYOLOGY. 



221 



Introduc- exists in its most distinct and apparently fleshy state, it 



tion. consists merely of a ligamentous or cellular substance, 



TheSenses. ^ppiigj qj, ji^g surface of" the lingual bone. It is never 



^^^/^^ furnished with muscles capable of producing any movement 



of extension or retraction, as in quadrupeds. 



Fishes cannot be said to be more highly favoured in re- 

 spect to the orgmis of touch than those of taste. The faculty 

 is greatly deadened over the general surface by the coating 

 of scales, and in the particular members by the inflexibility 

 of the rays. It is chiefly confined to the lips, and even 

 these parts in many species are themselves as hard and in- 

 sensible as bone. Certain soft and delicate appendages 

 called barbels, possessed by many species, such as the Cod 

 and Loach, are supposed to enjoy a more delicate percep- 

 tion of the sense of touch ; and among the Sclerogenida 

 there are many species that have one or more rays of the 

 pectoral detached from the membrane, so as to become 

 truly delicate, flexible fingers, not for prehension but for 

 touch. The common Gurnard has been seen in a clear sea 

 swimming along near a sandy bottom, and exploring it with 

 these special organs of touch. It is by means of the dermis 

 that that peculiar matter, so remarkable for its silvery me- 

 tallic lustre, and which bestows so much of brilliancy upon 

 the class, is secreted beneath the scales. It is composed of 

 of small polished plates resembling burnished silver, and 

 capable of being removed by washing, either fi'om the skin 

 itself, or from the inferior surface of the scales. It is this 

 substance that is used in the formation of false pearls. It 

 is also secreted by many species in the thickness of the 

 peritoneum, and in the envelopes supplied by that part to 

 particular viscera, especially the swimming bladder. 



It thus appears that the external senses of fishes convey 

 to them few lively or distinct impressions ; and by what- 

 ever scenes in nature they are surrounded, their perceptions 

 are probably indistinct and dull. Their sexual emotions, 

 cold as their blood, indicate only individual wants. Few 

 species pair, or enjoy any connubial gratification, for the 

 males seek the eggs rather than the females which deposit 

 them, and neither sex ever recognises its offspring. At 

 least the exceptions to these general laws are extremely 

 few, and when they occur they are of the lowest animal 

 description. A pair of Congers are so dead to external im- 

 pressions at the time of sexual congress, and so automati- 

 cally, as it were, engaged, that they have been taken 

 by the hand together out of the water. Sharks and 



Fig. 51. 



Pectoral fins and claspers. or intromittent origans of the male Bemiscyllium 



trispeculare. 



Rays have special organs that make some approach to those 

 of the two higher classes of vertebrals. We have no means 

 of knowing much of the loves of a Dog-fish or Skate, but 

 the prevailing economy of fishes may be said in all these re- 

 spects to be exactly the reverse of that of birds. These 



gay creatures of the sky have the power of surveying dis- Introduc- 

 tinctly at a glance an immeasurable extent of horizon ; tion. 

 their acute perception of hearing appreciates all sounds, TheSenses. 

 and every intonation ; and their glad voices are exquisitely ^"^^/"^ 

 skilled in their production. Though their bills be hard, 

 and their bodies covered by down and feathers, they are by 

 no means deficient in the sense of touch. They enjoy all 

 the delights of conjugal and parental affection, and perform 

 their incumbent duties with devotedness and courage ; they 

 cherish and defend their offsjiring, and will sometimes die 

 in their defence ; and of all the wonderful labours of instinc- 

 tive art, none is so beautiful as the formation of their mossy 

 dwellings. With what deep and continuous affection does 

 the female brood over her cherished treasures ! how un- 

 wearied is the gallant male in his tender assiduities, and in 

 the rich outpouring of that varied song by which he seeks 

 to soothe her sedentary task ! The same principle of at- 

 tachment and discrimination is even made available in a 

 state of domestication by the skill of all-engrossing man. A 

 bird acquires a knowledge of its master, and submits to and 

 obeys that master's will ; and the proud falcon, which in its 

 natural state 



" Doth dally with the wind, and scorn the sun," 

 will wheel in airy circles over a well-trained dog, or stoop 

 its boldest flight at some familiar urchin's call. Other 

 species will even imitate man's noblest faculty, the power 

 of speech, — and it is thus with somewhat doubtful feelings 

 that we deny to them the gift of reason. 



But the silent dweller in the deep knows few attachments, 

 expresses no language, cherishes no affections. Construct- 

 ing no dwelling, he merely shelters himself fi'om danger 

 among the cavernous rocks of the ocean, or beneath the 

 murky shade of the overhanging banks of rivers ; and the 

 cravings of hunger seem alone to exercise a frequent or 

 influential action over his monotonous movements. We 

 must not, however, suppose that the life of fishes is not one 

 of enjoyment, for we know that the great Creator " careth 

 for all his creatures ;" and it ought perhaps rather to be 

 said that we cannot appreciate tlie nature of their feelings, 

 than that they are in any way fore-doomed to a negation of 

 pleasure. Assuredly, however, the hand of nature has been 

 most prodigal in bestowing on their external aspect every 

 variety of adornment. Their special forms are infinite, their 

 proportions often most elegant, their colours lively and diver- 

 sified, and nothing seems wanting in them to excite the 

 admiration of mankind. Indeed it almost appears as if this 

 prodigality of beauty was intended solely for such an end. 

 The brightness of metallic splendour, the sparkling bril- 

 liancy of precious gems, the milder eflulgence of the hues 

 of flowers, all combine to signalize fishes as among the most 

 beautiful objects of creation. When newly withdrawn fi-om 

 their native element, or still gliding submerged in its liquid 

 coolness, their colours, fixed or iridescent, are seen mingling 

 in streaks or bands, or broader flashes, always elegant and 

 symmetrical ; sometimes richly contrasted, sometimes gra- 

 dually softened into each other ; and in all cases harmoniz- 

 ing with a chaste fulness of effect, which Titian or Rubens 

 might envy, but could never equal. For what reason, then, 

 it has been asked, has all this adornment been so lavishly 

 bestowed on creatures which can scarcely perceive each 

 other amid the dim and perpetual twilight of the deep ? 

 Shakspeare has already said that there are " more things in 

 heaven and earth than are dreamt of in our philoso])hy ;" 

 and we fear it is no answer to the foregoing question to 

 add, that the same observation applies with even greater 

 truth to the " waters beneath the earth" 



SECTION VI. — THE NUTRITION, MANDUCATION, AND DEGLU- 

 TITION OF FISHES. 



The nutritive functions of fishes follow the same order 



