CARTILAGINOUS FISHES. 



287 



the deviations of winch from the usual form 

 of fishes are beyond the power of words to 

 describe, and scarcely of the pencil to draw. 

 In this class we have the Pipe Fish, that al- 



frost not lying over them as it does elsewhere, and dig 

 them out in heaps. The practice of searching for eels 

 in mud in cold weather is not confined to this country ; 

 Dr Mitchill, in his paper on the Fishes of New York, 

 published in the Transactions of the Literary and Philo- 

 sophical Society of that city, says, " In the winter eels 

 lie concealed in the mud, and are taken in great num- 

 bers by spears." Thus imbedded in mud, in a state of 

 torpidity, the eel indicates a low degree of respiration. 

 Dr Marshall Hall has shown that the quantity of respi- 

 ration is inversely as the degree of irritability. With a 

 high degree of irritability and a low respiration, co-ex- 

 ist 1st. The power of sustaining the privation of air 

 and of food ; 2nd. A low animal temperature ; 3rd. 

 Little activity; 4th. Great tenacity of life. All these 

 peculiarities eels are well known to possess. The 

 high degree of irritability of the muscular fibre ex- 

 plains the restless motions of eels during thunder- 

 storms, and helps to account for the enormous cap- 

 tures made in some rivers by the use of gratings, boxes, 

 and eel pots or baskets, which imprison all that enter. 

 The power of enduring the effects of a low temperature 

 is shown by the fact, that eels exposed on the ground till 

 frozen, then buried in snow, and at the end of four days 

 put into water, and so thawed slowly, discovered gradu- 

 ally signs of life, and soon perfectly recovered. 



The mode by which young eels are produced appears 

 to have long been a subject of inquiry, and the notions of 

 the ancients as well as of some of the moderns were nu- 

 merous and fanciful. Aristotle believed that they sprang 

 from the mud ; Pliny, from fragments which were sepa- 

 rated from their bodies by rubbing against rocks; others 

 supposed that they proceeded from the carcasses of ani- 

 mals ; Helmont believed that they came from May-dew, 

 and might be obtained by the following process : " Cut 

 up two turfs covered with May-dew, and lay one upon 

 the other, the grassy sides inwards, and thus expose them 

 to the heat of the sun; in a few hours there will spring 

 from them an infinite quantity of eels." Horse-hair 

 from the tail of a stallion, when deposited in water, was 

 formerly believed to be a never-failing source of a supply 

 of young eels. It was long considered certain that they 

 were viviparous : this belief had its origin probably in 

 the numerous worms that are frequently to be found in 

 various parts of the bodies of eels, sometimes in the se- 

 rous cavities, at others in the intestinal canal. Rudol- 

 phi has enumerated eight different species of entozoa 

 common to fresh-water eels. The enormous number of 

 young known to be produced by eels is a good negative 

 proof that they are oviparous ; viviparous fishes produc- 

 ing, on the contrary, but few young at a time, and 

 these too of considerable size when first excluded. Hav- 

 ing devoted time and attention to the close examination 

 of numbers of eels for many months in succession, the 

 further details of which will be found in Mr Jesse's se- 

 cond series of Gleanings in Natural History, I need only 

 here repeat my belief that eels are oviparous, producing 

 their young like other true bony fishes. 



" The sexual organ consists of two long narrow sacs ex- 

 tending one on each side of the air-bladder throughout the 

 whole length of the abdominal cavity, and continuing for 

 two inches posterior to the vent. The membranes form- 

 ing this tubular sac, secreting on the inner surface the 

 milt of the male, and affording attachment for the ova in 

 the female, are puckered or gathered along the line of 

 junction to the peritoneal covering of the spine, and the 

 free or loose floating edge is therefore thrown into creases 

 or plaits like a frill. It is probably from this folded 

 or convoluted appearance the sexual organs of the eel 



most tapers to a thread, and the Sun Fish, 

 that has the appearance of a bulky head, but 

 the body cut oft' in the middle ; the Hippocam- 

 pus, with a head somewhat like that of a horse, 



have frequently been called fringes. By the kind- 

 ness of my friends Mr Clift and Mr Owen, of the Royal 

 College of Surgeons, I have had the pleasure of seeing 

 some drawings belonging to the collection of John Hun- 

 ter, in which these peculiarities of the sexual organs in 

 the eel are beautifully exhibited in various magnified re- 

 presentations." 



Dr Mitchill of New York, whose paper on Fishes has 

 been already referred to, says " the roes or ovaria of eels 

 may be seen by those who will look for them in the pro- 

 per season, like those of other fishes." 



Eels that have lain in brackish water all the winter 

 under the constant influence of the higher temperature 

 of that locality, probably deposit their spawn earlier in 

 the spring than those which have passed the winter in 

 places from which there existed for them no possible 

 egress. In the Mole, the Wey, the Longford river, and 

 in some large ponds, the eels in the spring of 1833 did 

 not deposit their spawn till near the end of April ; but in 

 two eels from Sheerness received and examined on the 

 18th of May, the internal appearances induced me to 

 believe that the roes had been passed some time. How 

 long the ova remain deposited before the young eel is 

 produced, is, I believe, unknown. The duration of this 

 interval is very variable in different fishes. The roe of 

 the herring, deposited at the end of October or the be- 

 ginning of November, is said to become living fry within 

 three weeks : the ova of eels, the produce of which is 

 very small, do not probably require a longer period. 

 Both the parent eels and the fry occupying the brackish 

 water appear to have the power of going either to the 

 salt water or to the fresh without inconvenience, from 

 the previous preparation which the respiratory organs 

 have undergone, and many of both are found in pure sea 

 water : the great bulk of the young, however, certainly 

 ascend the stream of the river, and their annual appear- 

 ance in certain places is looked for with some interest. 

 The passage of young eels up the Thames at Kingston 

 in the year 1832 commenced on the 30th of April, and 

 lasted till the 4th of May; but I believe I am correct in 

 stating that few young eels were observed to pass up the 

 Thames either in the year 1834 or 1835. Some notion 

 may be formed of the quantity of young eels, each about 

 three inches long, that pass up the Thames in the spring, 

 and in other rivers the beginning of summer, from the 

 circumstance that it was calculated by two observers of 

 the progress of the young eels at Kingston in 1832, tiiat 

 from sixteen to eighteen hundred passed a given point in 

 the space of one minute of time. This passage of young 

 eels is called ee\-fare on the banks of the Thames, 

 the Saxon word signifying to go, to pass, to travel ;* and 

 I have very little doubt that the term Elver, in common 

 use on the banks of the Severn for a young eel, is a mo- 

 dification or corruption of eel-fare. 



" When the elvers appear in the Severn, they are 

 taken in great quantities with sieves of hair-cloth, or 

 even with a common basket, and, after being scoured 

 and boiled, are offered for sale. They are either fried in 

 cakes or stewed, and are accounted very delicious." 



There is no doubt that eels occasionally quit the 

 water, and when grass meadows are wet from dew, or 

 other causes, travel during the night over the moist sur- 

 face in search of frogs and other suitable food, or to 

 change their situation. Some ponds continually produce 

 eels, though the owners of these ponds are most desirous 



* A pedestrian on the road is called "away-faring man;-' 

 and hence, also, the price for travelling 1 by a conveyance is 

 called " the fare." We have also ''thoroughfare," &c. 



