14 



ACANTHOPTERYGII. 



species at least, there is a sense in the skin analogous 

 to what we call touch. That the common trout (sal- 

 m>fario) is pleased by tickling is so familiarly known 

 that it has been made the foundation of a common 

 saying on the effect of flattery : 



1 If you tickle the trout, 

 You'll soon have him out ; 

 But handle him rough, 

 And he's sure to be off." 



The fishes of this division have no external ears, nor, 

 indeed, have any of the osseous fishes ; and in the 

 cartilaginous ones, the external orifices are exceed- 

 ingly small. In the external ear there are, instead of 

 the lamina and tympanum in the mammalia, certain 

 little balls of porcelain lustre suspended by a nervous 

 plexus ; but how the agitation of the water acts upon 

 them so as to'produce sound, or to what depth and in 

 what particular manner sounds are produced in, or affect 

 the water, is very little known, as we cannot bring it 

 to the test of our own ears, and it is not possible to 

 judge accurately of one sense from comparison with 

 another ; that sounds have a considerable effect upon 

 water is, however, clear, from the well-known fact 

 that a cannonade tranquillises the waves for some 

 distance round. Fishes have no voice when in the 

 water ; and those sounds which some of them make 

 when out of it are produced by convulsions of the gills 

 and gill-openings, and not by the mouth. There is 

 not, indeed, any organisation of the mouth or throat by 

 which sound could be produced. Touch, indeed, ap- 

 pears to be their only means of communication with 

 each other ; and that and sight are the senses upon which 

 they chiefly depend. Authors have, indeed, written 

 about the sense of smell in fishes, and pointed out 

 how trouts of taste, differing from our epicures, prefer 

 recent game to that which is high ; but the statements 

 are not very philosophic in themselves, and they are 

 opposed to all the facts of fishing with artificial bait, 

 which no fish refuses if it is skilfully made and well- 

 timed in the offer. The nervous enlargements at the 

 origin of the olfactory nerves are, indeed, in some 

 species, almost as large as the brain, but we know 

 little of their action. Taste there can be little or 

 none, from the readiness with which the same fish 

 catches again and again at the same artificial bait ; 

 and the whole internal surface of the mouth is of a 

 description to which we would not, from the analogy 

 of other animal structures, attribute much sensation 

 of any kind. It is true that fishes are affected by 

 impure water ; but the pain which it gives them ap- 

 pears to .be chiefly, if not wholly, felt in the gills. In 

 these cases they come to the surface, and pant and 

 gasp there as if they were anxious wholly or partially 

 to breathe the air. That may be seen in places where 

 flax is much cultivated and prepared. When that 

 plant is macerated, or steeped, in order to make the 

 fibres part from the leaves, it communicates a most 

 offensive intoxicating poison to the water ; and when 

 the pits are allowed to empty themselves into streams, 

 the fish are instantly affected and come to the sur- 

 face, come to more speedy and certain death indeed, 

 for the most virulent part of the poison is the lurid 

 scum which floats on the surface. 



The eyes of fishes are much more perfectly formed 

 than their other organs of sense, and we are much 

 better acquainted with their action. They even ob- 

 serve a very minute object when the water is dark 

 and the surface ruffled. But in a clear day rivtr fishes 

 can see a shadow passing along the water, and are 



alarmed by it. Their eyes are admirably formed both 

 for protection and for readiness in the use. The surface 

 is in general flat, and the common integument passes 

 over the eye without any duplicature or eyelid, except 

 in a few very peculiar species ; and thus the most 

 violent agitation of the water produces much less 

 effect upon the eye of a fish than a gentle breeze does 

 upon the human eve. Such an eye could not indeed 

 exist exposed to the air, or to any drying element ; 

 and hence in all eyes that are to be used in the air, 

 there are either moveable eyelids, as in the mammalia, 

 or nictitating membranes, as in birds, by the applica- 

 tion of which the coat of the eye is kept moist and 

 transparent. But the eye of a fish, from the nature 

 of its element, and the adaptation of the structure to 

 that element, is always ready ; and in all states of the 

 water in which the muscular action of the fish can 

 keep its place, the eye can see the smallest substance. 

 Turbid water, or even rolling pebbles, can do little 

 injury to an eye so flat. But in proportion as the 

 external surface of the eye is flat, the crystalline lens 

 is convex. It is, indeed, nearly a perfect sphere ; and 

 thus the eye has great magnifying power ; although 

 it appears to have considerable range of focal length. 

 The eye of a fish is one of the most curious varieties 

 of that most interesting of organs. See the article 

 EYE. 



As this division is considered by Cuvier as con- 

 taining the most perfect fishes, or the types of the 

 class, the mode of their respiration and the circulation 

 to which it is necessary, must be regarded as that 

 which is most perfectly expressive of an inhabitant of 

 the waters a breather by means of gills, the fibres 

 of which play freely on that fluid. The structure and 

 form of gills will be found explained in the article 

 FISHES ; so that we have here only to remark that 

 the heart of fishes is small and single. The auricle 

 receives tho blood from the body and sends it to 

 the ventricle ; and that propels it through an artery 

 which is finely ramified over the gills. From the gills 

 it returns by veins, small at first, but meeting and 

 emptying themselves into the aorta or large artery, 

 which lies along the under side of the spine ; and 

 from that it is sent over the body, returning by veins 

 to the auricle of the heart, but the veins are often 

 much dilated, and the circulation in them very slug- 

 gish. The gills and the parts near the spine are the 

 only ones that bleed copiously when wounded. 



Such is a very short summary of the general 

 structure of osseous fishes ; and we should now point 

 out the characters of the order. Of these, however, 

 there is hardly one constant, unless it be the spiny 

 rays in the fins, and even that is not absolutely con- 

 fined to the order, and is very variable in it. The 

 particulars must therefore be reserved to the families 

 or subdivisions, of which Cuvier's list is subjoined ; and 

 the characters and subdivisions will be found noticed 

 under the several titles. 



FAMILY I. Percoideas, the perch family. They 

 are numerous, and generally wholesome and rather 

 palatable as food. 



FAMILY II. EnaplcccephalefE, armed-headed fishes. 

 These have the head variously furnished with spines, 

 plates, or other appendages. 



FAMILY III. Scieenidcc. 



FAMILY IV. Sparidte, the gilt-head family. 



FAMILY V. Muenidee. 



FAMILY VI. Sauameptercec, scale-finned fishes. 



FAMJLY VII. Scombcridv, the mackerel family, 



FAMILY VIII. Tartioidte, tH? riband-fish family. 



