The scales of a fish are for the purpose probably of defending it from its enemies in the way of associates of a vegetable or animal parasitic or devouring nature. If one be lost, it is again supplied in a manner similar to the supply of a lost nail in the human being. Glands are situated under the so-called lateral line and on the head of the fish, and from them a sort of varnish of mucus is perspired, without which fish cannot live long. When from any cause the supply fails, parasitic growths make their appearance, and after them malignant ulcers, and finally death. Roach about spawning time are usually rough and devoid of a plentiful supply. The roughness is caused by a sort of loosening of the scales. This soon after the deposition of ova, however, subsides, and an abundance of mucus makes it very unpleasant to handle the fish at all. The scales of fishes are divided into four classes, which are termed by Agassus-cycloid, from the Greek eidos, resemblance, and cyclos the circle; ctenoid, from ctenis, a rake; ganoid, from ganos, brilliancy; and placoid, from plax, a flat level surface.

Now as to the senses of fishes, which, after all, is to anglers the most important consideration of all.

First I will advert to sight. This is, unquestionably, the best developed sense in fishes, especially in the game fishes. In fish the eyes are variously placed, some having them so situated that a forward, backward, upward, and downward movement may be made, as in some of the carp family bred by the Chinese, termed "telescope" fish; in others, such as trout, the sight is vastly more developed, but the movement of the eye is more confined, hence I do not think a trout can see back, and in the case of the pike, where the prey is seized chiefly above the destroyer near the surface, the eyes are near the top of the head, and I opine and have seen nothing to alter the opinion, that the pike cannot, without great exertion and an anomalous arrangement of position, pick a bait from the bottom of the water. The angler may be quite sure that when he can see a fish that fish can invariably see him. An interesting question has recently arisen in an American sporting paper as to "colour " blindness in trout of certain waters. I am disposed to believe, without here giving my reasons for it, that in some cases trout are afflicted, if not with colour blindness, with certainly an unreasonable and unaccountable desire for a certain hue which rarely, but in some cases, disappears. I shall, however, discuss the matter in the chapter on Trout.

The senses of smell and taste have been referred to to some extent in a recent chapter, wherein I touched on the subject of baits, and need little, if any, further consideration. Whilst I concede the power of smelling to be tolerably acute, I am convinced that the sense of taste is very imperfect. Mr. Pennell gives as a reason for believing that fish have a

poor power of palate, the fact that they are "often unable to distinguish poisonous substances, and are frequently accordingly destroyed wholesale by poachers." It seems to me that these are very insufficient grounds for assuming an absence of taste. I doubt not but that I or the nearest druggist could compound savoury but fatal dishes ad infinitum, and even Mr. Pennell's educated palate would fail to distinguish the poisonous agent. However, he is quite right in the assertion which follows, that the sense of taste (if it amount to that) is more developed in herbivorous than in carnivorous fishes.

The sense of feeling, or mechanical perception, is without doubt also but feebly developed, except in such fish as the Silurus glanis, and generally barbed or bearded fishes, such as the barbel and gudgeon. In these the sense of sight is in many cases imperfectly developed, and the tentacula are as auxilliaries brought into requisition. The sense of feeling in its subjective aspect is also feeble. A shark, Mr. Pennell tells us, will be seemingly unconscious of serious injury unless it is disabled, and we know how trout will take a hook in its mouth, and a pike a gorge bait with treble hooks in its mouth and another hook and half digested lead in its stomach. Mr. Pennell once caught a perch with its own eye; and this incident reminds me that on one occasion I performed the operation on a large tame carp of cutting its eye from its head, from which it hung suspended by the optic nerve-having been partially torn out. The carp the same evening responded to its keeper's whistle to be fed, and did feed.

Speaking of calling fish reminds me of the final sense on which it is here necessary specifically to remark, viz., hearing. That fish do hear is undoubted; but the medium of the water being denser the sound made in air is not heard, I believe, in water unless it be sufficiently loud to produce well-defined mechanical vibrations in the water. For example, one may speak as loudly as inclined in the punt within a few yards of a wily old chub, but no result is apparent. The fish whose sight is so keen and whose fears are so instantly aroused as to perceive in the shadow of a flying bird an enemy, cannot hear the reverberation of the voice-for this assumption is fair from its timorous character; but fire off a gun near it as I have done, hidden so that no smoke or flame can be possibly seen by the fish, and away darts Cyprinus cephalus to deep water. Again, I have seen the small fish leap bodily out of the water on the firing of a frigate's 24-pounder. Of course I know that these results are substantially denied by Ronalds in his book, but I can conceive of his experiments being faulty, and his gun of light detonation, both of which possible causes of his opinions could not have operated in my own experiments. Again, notwithstanding my experience, I am confronted by the fact that persons whistle and call

tame carp. How shall we get out of the dilemma ? I invite the reader to try experiments himself.

So far I have spoken of sounds made in the air being practically unheard in the water. Now for a different aspect of the affair.

The chub of which I spoke above did not perceive your voice when you shouted without materially moving yourself; but assume that he is in the same position, and stamp your foot on the floor of the punt, the chub disappears instantly, and the angler cannot get him to return that day at least. The deduction is evident, and when fishing the tyro should bear in mind that it is infinitely worse to stamp the feet or move about in the punt or walk heavily on the bank than to talk or sing or whistle. Sound made on the surface or in water travels for miles, and fish in a well-fished river know the difference between sounds as well as the angler.

Growing out of the above remarks are various questions of great interest to the amateur as well as professional ichthyologist. A slight consideration of some of these cannot but be of service to the anglernaturalist, inasmuch as that the necessity for personal observation will be made manifest. The careful observer of fish life is usually a better angler than the careless and unobservant fisher. This is certain.

Do fish sleep? An equivocal answer can only be given. My own impression is that they do; but when I say this let it not be supposed that I confuse their slumber, coma, or rest-call it what you like—with the sleep of animals. It is the same only in generic kind, inasmuch as that it relieves the functions as analogous slumber does in the higher animals. To understand the meaning I wish to convey it is necessary to bear in mind that the fish is eminently endowed with muscular and consequently great locomotive power. Moreover, as it consumes but little oxygen, the waste of tissue is not great, hence fish have been known to do without food for a great length of time. Similarly the stress on the vital powers is not great, compared with that produced by the difficulties of movement in land animals.

These facts-viz., great muscular power, easy locomotion, and small consumption of oxygen, being borne in mind, we can understand why the necessity for sleep is small, and are prepared to find that fish sleep but little. And what are the observed facts? I have, so has every angler, observed the pike lie in the sunshine oblivious of the gently lowered bait, and even unconcerned when gently touched. I have noticed that fish seem to retire towards the period of night before dawn, and Mr. Chas. Capel, of Foot's Cray Fishery, wrote to the Field some little time ago saying in effect that on his entering his fish house at night and striking a light he has seen the young trout rise from their recumbent position on the gravelly bottom of the trough and resume their accustomed vivacity.

Fish presumably therefore do sleep-but lightly and seldom. Do fish hybernate? naturally follows the remarks on sleep, and again I cannot but assert that I believe some do, and that nearly all are capable of doing so. The well-known instance of the Ceylon mud fish, and fish of other waters in India, which bury themselves during the dry season and emerge on the rains filling the watercourses and hollows, is sufficient to show that at least one fresh-water fish indubitably hybernates. Again, the eel retires in winter to either the still deep and warm parts of the water, or buries itself in the mud in a lethargic condition, to be revived at the approach of spring. The tench also occasionally may be found buried almost completely, and I have, before now, taken him from the mud in a state resembling the lethargy of complete hybernation as exhibited by the dormouse or bat. Cold seems the chief agent in producing this state, and Franklin recites a case in which some perch were frozen completely hard, and were so brittle as to be easily broken, but were afterwards resuscitated on being gradually thawed. Instances of the same kind, but unfortunately not quite so well and definitely observed, have come within my own experience. In the example given by Franklin it is impossible to avoid the conclusion that remarkable vital powers under total suspension of animation were exhibited. The sum of evidence is that such power-by the bye, the existence of an analogous power in warm blooded animals is not proved to be impossible-is possessed generally by cold blooded creatures. The famous, and in some cases well authenticated stories of the "toad in the hole," or in the middle of trees, brick walls, &c., are forcible circumstances not to be forgotten. It should be added that the gills of such fish as seem fitted for hybernation, partial or entire, have opercula or gill covers with a membrane capable of being almost entirely drawn over the opening. The object of this seems to be the retention of moisture, and the preservation of the branchæ from impurity calculated to injure the texture.

The capacity for living out of water is very great in some specimens of fresh-water fishes. The carp is not infrequently in Germany and other continental countries kept suspended in nets, the only necessary condition being that a continual but not copious supply of fresh water be thrown over the body of the fish. Fish so treated are said to be fed on bread soaked in milk with occasionally a little brandy added. I have known perch to live twenty-two hours in a cool damp situation out of water, and I believe that eels, if carefully kept damp, would live longer.

The diseases of fish are many, and chiefly parasitic. Not only are the parasitic growth animal, but they are of vegetable growth also.

The internal parasites of fish are in number legion. A complete list would be a herculean task, as may be inferred from the statement of Dr.

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Cobbold (Synopsis of the Distomidae) that of 344 species of "fluke" (or Trematoda) no less than 126 belonged to fishes. The same author also adds that this species of entozoa are particularly plentiful in the stickleback, minnow, tench, perch, pope, trout, salmon, and still more abundant in pike, barbel, bream, eel, &c."\

One of the most interesting of these peculiar creatures belonging to the above genus is the Gyrodactylus elegans, which I have more than once extracted from the gills of the bream. I read that Siebold and Creplin both found members of the same family attached to the fins, but I think it more properly is an internal parasite, and have so considered it. In this case an almost completely developed embryo could be perceived contained in the abdominal cavity.

Of the order of Nematoda, or round worms, I have repeatedly met members of the family Anguillulidæ in nearly all fresh-water fish. Of course, I am aware that some of the species, such as the vinegar eel, are non-parasitic, but others are not so, which is proved by my detection of them in the digestive system of the eel. It is an exceedingly minute worm, not often of a greater length than the tenth of an inch. Its tenacity of life is very remarkable. The observations of Needham, Bauer, and Dujardin have shown that the animal is capable of revivification even after a period of desiccation extending over five years.

The "thorn-headed" worms are particularly numerous in fish, especially in roach. I have found the large intestine of this fish completely studded with the Echinoshynchus anthuris, whilst a trout caught in June, 1877, exhibited a great many of a kindred species, the Echinoshynchus proteus. Its head is cone-shaped, studded with incredibly sharp thorns, set barb wise. I am inclined to attribute the wasting or atrophy to which the fish is subject to the presence of members of the Echinoshynchidae.

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I have thus briefly and scantily touched upon a few of the more minute and curious parasites which infest fish to my own knowledge. I now come to notice the large and important order of Cestoda, or tapeworm," specimens of which I have more frequently than any other parasite taken from the intestines of our fresh-water fish. In order to obtain a correct idea of their nature as regards fish, it must be borne in mind that, as a general fact, the tapeworms found in fish are immature or larval cestodes, waiting to find themselves inside the heron, or plover, gull, diver, duck, or some such water bird before developing to maturity. Therefore, such worms usually display considerable difference in structure to those inhabiting mammals, "being commonly furnished," says Dr. Cobbold, "with special tentacular hooks, appendages employed as supplementary organs of boring and anchorage." There are variations from this, how