or Eel, in ichthyology; a genus of fishes, belonging to the order of apodes. The head is smooth; there are ten rays in the membrane of the gills; the eyes are covered with a common skin; and the body is cylindrical and slimy. There are seven species, distinguished by their fins, tails, &c. The most remarkable are,

1. The anguilla, or common eel, is very frequent in all our fresh waters, ponds, ditches, and rivers; according to Mr Pennant, it is the most universal of fish; yet is scarce ever found in the Danube, though very common in the lakes and rivers of Upper Austria.

The eel is very singular in many things relating to its natural history, and in some respects borders on the nature of the reptile tribe. It is known to quit its element, and during night to wander along the meadows, not only in order to change its habitation, but also for the sake of prey, feeding on snails as it passes along. During winter it beds itself deep in the mud, and continues in a state like the serpent-kind. It is very impatient of cold, and will eagerly take shelter in a wisp of straw flung into a pond in severe weather, which has sometimes been practised as a method of taking them. Albertus affirms, that he has known eels to take shelter in a hayrick; yet all perished through excess of cold. It has been observed in a river of England called the Nene, there is a variety of small eel, with a lesser head and narrower mouth than the common kind, that is found in clutters in the bottom of the river, and is called the bedeel: these are sometimes roused up by the violent floods, and are never found at that time with meat in their stomach.

Eels are extremely voracious, and destructive to the fry of others. No fish lives so long out of water as the eel; and it is so extremely tenacious of life, that its parts will move a considerable time after they are flayed and cut in pieces. They vary much in their colours, from a foot hue to a light olive green; and those which are called silver eels have their bellies white, and a remarkable cleanness throughout. Besides these, there is a variety of this fish known in the river Thames by the name of grizzi, and about Oxford by that of grizz or gluts. These are scarce ever seen near Oxford in the winter; but appear in spring, and bite readily at the hook, which common eels in that neighbourhood will not. They have a larger head, a blunter nose, thicker skin, and less fat, than the common sort; neither are they so much esteemed, nor do they often exceed three or four pounds in weight.—Common eels grow to a large size, sometimes weighing 15 or 25 pounds; but that is extremely rare. Mr Dale indeed, in the Philosophical Transactions, and some others, bring instances of eels much exceeding that size; but Mr Pennant supposes them to have been congers, since the enormous fish they describe have all been taken at the mouths of the Thames or Medway. The Romans held eels very cheap, probably on account of their likeness to snakes. On the contrary, the luxurious Sybarites were so fond of these fish, as to exempt from tribute of every kind those persons who sold them.

There is scarce any animal the generation of which has puzzled the learned more than this. Aristotle first broached an opinion that eels were of no sex, nor did propagate their species like other animals, but were equivocally gendered of the mud; and as wild and absurd a system as this is, there have not been wanting many, even in these latter and more enlightened times, who have given into it. But there is now no room to doubt that all animals are produced by the copulation of parents like themselves; and the finding of eels in new ponds is easily accounted for from the above mentioned circumstance of their migration. Dr Plot, and many others, have given accounts of whole droves of them leaving one ditch or pond to go to another.

Though the learned world at this time generally allows that eels are produced like other animals, by parents of their own kind, yet there remain many doubts about the manner in which the generation is performed. Some allow the eels to be, like the generality of other animals, of different sexes in the different individuals; and others affirm that they are all hermaphrodites, each having the parts of generation of both sexes. Rondeletius affirms that they are of both sexes; and Mr Allan, who has given a very curious paper concerning them in the Philosophical Transactions, is of the same opinion; and both say, that the parts of the sexes may be discovered on a careful inspection; and some are found to be males, and others females; but these parts are, in both sexes, they say, buried in a large quantity of fat; and they are of opinion, that hence proceeded the mistake of Aristotle and his followers, who, not being able to find these parts, concluded that they did not exist at all. Among those who allow the eel to be produced, like other animals, from animal-parents which have the sexes, some are of opinion that they are viviparous, and and others that they are oviparous; but Mr Chartwynd seems to have determined this controversy by observing, that if the aperture under the belly of the eel, which looks red in the month of May, be cut open at that time, the young eels will be seen to come forth alive after the operation. Mr Lewenhoeck says, that he found an uterus in every eel he examined; and therefore concludes, that they are hermaphrodites: and he supposes that they have no male parts of generation like those of other animals; but that the office of these is performed by a liquor analogous to the male seed of animals, which is contained in certain glands, situated in the inside of the uterus itself.

Eels have sometimes been met with in recent ponds, made at such a distance from any other water that we cannot reasonably suppose them to have migrated thither over land. But in these cases there is reason to believe, that the ponds have been supplied with them by the aquatic fowl of prey, in the same manner as vegetation is spread by many of the land-birds, either by being dropped, as they carry them to feed their young, or by passing quick through their bodies, as is the case with herons.

2. The conger, or conger-eel, grows to a vast size. Dr Borlase informs us, that they are sometimes taken near Mount's-bay of 100 lbs. weight; and Mr Pennant assures us, that he has heard of some taken near Scarborough that were 10 feet and a half long, and 18 inches in circumference in the thickest part. They differ from the common eel in the following particulars: 1. Their colour in general is more dark. 2. Their eyes much larger in proportion.—3. The irides of a bright silvery colour. 4. The lower jaw is rather shorter than the upper. 5. The inside-line is broad, whitish, and marked with a row of small spots. 6. The edges of the dorsal and anal fins are black. 7. They have more bones than the common eel, especially along the back quite to the head. 8. They grow to a much larger size.

Congers are extremely voracious, preying on other fish, and on crabs at the time they have lost their shell and are in a soft state. They and eels in general are also particularly fond of carcasses of any kind, being frequently found lodged in such as are accidentally taken up.

The conger eels probably generate like the fresh-water species. Innumerable quantities of what are supposed to be their fry come up the Severn about the month of April, preceding the shads, which it is conjectured migrate into that river to feed on them; they are called elvers. They swarm during their season, and are taken in a kind of sieve made of hair-cloth fixed to a long pole; the fisherman standing on the edge of the water during the tide, puts in his net as far as he can reach, and drawing it out again, takes multitudes at every sweep, and will take as many during one tide as will fill a bushel. They are dressed, and reckoned very delicate.

These fish are an article of commerce in Cornwall; numbers are taken on that coast, and exported to Spain and Portugal, particularly to Barcelona.—Some are taken by a single hook and line, but (because that way is tedious, and does not answer the expense of time and labour) they are chiefly caught by bullers, which are strong lines 500 feet long, with Murana hooks, each eight feet asunder, baited with pilchards or mackerel; the bullers are sunk to the ground by a stone fastened to them: sometimes such a number of these are tied together as to reach a mile. The fishermen are very fearful of a large conger, lest it should endanger their legs by clinging round them; they therefore kill them as soon as possible by striking them on the navel. They are afterwards cured in this manner: They are slit, and hung on a frame till they dry, having a considerable quantity of fat; which it is necessary should exude before they are fit for use. It is remarkable that a conger of 100 weight will waste by drying to 24 lb.; the people therefore prefer the smallest, possibly because they are soonest cured. During the process there is a considerable stench; and it is said, that in the fishing villages the poultry are fed with the maggots that drop from the fish. The Portuguese and Spaniards use these dried congers after they have been ground into a powder, to thicken and give a relish to their soups. They are sold for about 40 shillings the quintal, which weighs 126 lbs. A fishery of congers, says Mr Pennant, would be of great advantage to the inhabitants of the Hebrides. Perhaps they would at first undertake it with repugnance, from their absurd aversion to the eel kind.

3. The sirens, or mud-iguana, a singular animal, first observed by Dr Garden of Charlottetown, and afterwards described by Mr Ellis in the Philosophical Transactions for 1766. It has gills, fins, and two feet; and is in length from 31 to 40 inches. It is an inhabitant of South Carolina, where it is found in swampy and muddy places, by the sides of pools, and under the trunks of old trees that hang over the water, and feeds on serpents. The feet appear like little arms and hands, each furnished with four fingers, and each finger with a claw. "The head is something like an eel, but more compressed; the eyes are small, and placed as those of the eel are. This smallness of the eye best suits an animal that lives so much in mud. The nostrils are very plainly to be distinguished; there, with the gills, and remarkable length of the lungs, show it to be a true amphibious animal.—The mouth is small in proportion to the length of the body; but its palate and inside of the lower jaw are well provided with many rows of pointed teeth: with this provision of nature, added to the sharp exterior bony edges of both the upper and under jaw, the animal seems capable of biting and grinding the hardest kind of food. The skin, which is black and full of small scales, resembles shagreen. These scales are of different sizes and shapes, according to their situation; but all appear sunk into its gelatinous surface: those along the back and belly are of an oblong oval form, and close set together; in the other parts they are round, and more distinct. Both the parts are mottled with small white spots, and have two distinct lines composed of small white streaks continued along from the feet to the tail. The fin of the tail has no rays, and is no more than an adipose membrane like that of the eel."

Dr Garden, in a letter to Mr Ellis, mentions a remarkable property of this animal, which is, that his servant endeavouring to kill one of them by dashing