Popular Science Monthly/Volume 61/September 1902/Eels and the Eel Question
| EELS AND THE EEL QUESTION. |
By M. C. MARSH,
U. S. COMMISSION OF FISH AND FISHERIES.
HISTORY recites an incident in which eels played the part of an executioner. The sentence a rich Roman, Vedius Pollio, passed upon his offending slaves was, 'Away to the Murænæ.' Slave-fattened eels were a Roman delicacy, and there was probably more gastronomy than justice in this edict. Ever since, and long before, for that matter, eels have occupied a unique and conspicuous place in popular interest. For the antiquity of their history, for the diversity of rôles they have played, for the many-sidedness of their career and in their importance, eels rival any group of animals below the sons of Adam.
If one were to follow eels—meaning here the common eel and not the lamprey, the Muræna, or the conger, which have histories of their own—backward in literature, the journey would probably reach the dawn of history. It would be difficult to say where they first entered written records, but that they have ever been the subject of curious attention is apparent. While they doubtless first engaged man's interest by way of his stomach, they were early found worthy of his intellect. Aristotle, wise man of the first European civilization, who explained all things, discoursed wisely and ponderously of eels, and the eel question may be said to have begun with him and his contemporaries. Three thousand years have passed, Aristotle is gone, but the eels and the eel question are still with us and the wise men of our century still concern themselves with both.
What is here called the eel question is one upon which the last word will not be said for some time to come. But it has changed its form and we have it upon a rather firmer foundation than that of the ancients. It began in the mystery attaching to the generation of eels. They were as the leaves of the trees for numbers; but the course of nature in reproducing other creatures each after its own kind did not seem to be exemplified in eels. Hence the mystery. 'Eel-spawn' was of the same material as a mare's nest and pigeon's milk.
The teachings on the subject were various. They were the offspring of Jove. This belief, however, originated in the humorous reflection of a Greek poet to the effect that as children of uncertain paternity were ascribed to Jupiter, he must be the progenitor of eels. They were said to be bred of the mud; of decaying bodies in the water; from dew, of a particular sort and falling in certain places; from the transformation of horse-hairs, and from electrical disturbances. A reverend bishop once communicated to the Royal Society a contribution on the subject of the origin of eels which in substance averred that he had seen young eels on the thatching of a cottage and that the eggs were adhering to the reeds of the thatching before they were cut, and were finally hatched on the roof by the heat of the sun. Helmont, an ancient writer, is specific and gives a recipe for producing eels. Two pieces of turf with May dew upon them were to be taken and the grassy sides apposed and placed in the sun. After a few hours an 'infinite quantity of eels' were generated. Helmont doubtless felt so sure of this that he regarded trying it a superfluous inconvenience, having no use for young eels. In the 'Piscatory Eclogues' is a reference in the same strain:
Say, canst thou tell how worms of moisture breed,
Or pike are gendered of the pickrel weed?
How carp without the parent seed renew
Or slimy eels are formed of genial dew?
Aristotle wrote: 'The eel is neither male nor female and is procreated from nothing.' He explained that they were produced from the slime of their bodies, which they scraped off against the pebbles or stones or by contact with each other in their sinuous migrations. This sounds fishy to the twentieth century, but it is easy to see that to Aristotle there should be something in it. There was the slime—that was evident enough. It was purposive in amount, it gave the slipperiness to a creature which is notoriously slippery. The remarkable abundance of eels required a theory of reproduction on a grand scale. And as for their rubbing together, a mass of wriggling and intertwining eels, the well-known 'eel-ball,' suggested nothing more strongly. What more simple and, for those times, natural!
Now there is a curious mixture of stumbling truth and preposterous error in the development of the eel question from this time forward. There was another teaching concerning the source of eels. Some who examined them discovered many small worm-like creatures in their internal machinery and insisted that these were the young and were produced alive from the parent eel—that is, that the eel was viviparous. This was certainly a much more natural and credible explanation, but it was scorned by Aristotle and Aristotle was correct. He said they were not eels, but were worms, and modern observations sufficiently uphold him. Yet the contrary opinion was held by the scientists of the middle ages, and names which are written high and imperishably on the scroll of fame subscribed to it. Leeuwenhoek, the discoverer of bacteria, and the renowned Linnæus believed that eels were not spawned and hatched but were born.
This idea, entirely erroneous, was corroborated later by a correct observation. This time it was in another direction that the investigator came to grief—so slippery was the eel question. He was not examining an eel, but an eel-pout, a fish very far removed from the eel, but so resembling it externally that the ichthyologists have, for a specific name, called it anguillaris, eel-like. And it has been popularly known as 'mother-of-eels. 'This eel-like fish is really viviparous, it produces its young alive, and they resemble small eels. The learned doctor thought he had solved the eel question. But he hadn't. To add to the confusion, another authority reviewed this work on the eel-pout and decided, being influenced by the previous real mistakes of the same nature, that the supposed young eels were only worms. This was plausible, yet he was wrong, for they were undoubtedly legitimate little eel-pouts, mistaken for little eels. Every one, it appears, who took up the question, managed from a basis of truth to reach a wrong conclusion.
Aristotle held that eels were also produced from the 'bowels of the earth,' by which he meant nothing more than common earthworms, which he curiously conceived to be thus related to Mother Earth. Other opinion maintained that eels were the offspring not of eels, but of other kinds of fishes, or of animals that were not even fishes. This heterodoxy was too much for Aristotle, but to this day is prevalent in some form among eel fishermen in various parts of the world. As for instance, that the 'aal-mutter' referred to, the eel-pout, really produces eels; that eels pair with water snakes; and in Sardinia that the well-known Dytiscus beetle is responsible for eels.
If these conflicting theories seem to us a ludicrous and amusing hodge-podge, it must not be forgotten that they were the wisdom of bygone days. Out of them the eel question resolved itself into a serious problem which interested the whole biological world, and to which the first talent in science addressed itself and on which voluminous and pretentious treatises appeared. Buff on, the naturalist, remarked that he considered the question of the generation of eels one of the most puzzling in natural history. Very appropriately it remained for the century of Isaac Walton to first assert that eels were not the subjects of a special dispensation for their replenishment, and that the mystery of their generation was the same mystery that envelops the rest of the kingdom of life. This not very brilliant announcement seems to have been put forth as a purely academic deduction. There were no observations in the modern sense, and the author of the 'Compleat Angler' was not particularly enthusiastic over it. He merely mentions it without subscribing, and says: 'But most men differ about their breeding,' and then after citing at some length what 'some say' and 'others say,' remarks: 'But that eels may be bred as some worms, and some kinds of bees and wasps are, either of dew or out of the corruption of the earth, seems to be made probable by the barnacles and young goslings bred by the sun's heat and the rotten planks of an old ship, and hatched of trees.'
The passing of Aristotelianism and the revival of the sciences, in the sixteenth century, was the occasion of this renewed interest in eels. It was not, however, until the eighteenth century that sex in eels was definitely recognized. Sancassini, a surgeon of Comacchio, in Italy, visited the eel fisheries at that famous place of eels, and chancing to be struck with the appearance of a large one, his professional instinct led him to use his knife. The result caused him to send it to Vallisneri at the University of Padua, who recognized with enthusiasm the true ova and forthwith communicated this fact to the Academy at Bologna. Vallisneri has since been appropriately honored by the bestowal of his name upon a water plant well known to all—eel-grass. But the immediate effect of his announcement was an eel controversy. Eels became the burning topic of the hour among the professors, the best-known names of the time are associated with the discussion, and Bologna became the storm-center of the eel question. Another specimen similar to the first increased the agitation. But Valsalva, of anatomical fame, showed that there were certain appearances in almost any fat and well-favored eel that strongly simulated what Vallisneri had described, and in brief, hinted that the alleged eggs were globules of uninteresting adipose. . An enthusiast offered a reward for an eel that should contain undoubted eggs. Of course he got it. His joy was short-lived, for a critical inspection showed that mercenary considerations had led the fisherman to fill the specimen with foreign eggs. This irreverence, and at this juncture, disturbed the seriousness of the situation and the eel question slumbered for over half a century. Then, again from Comacchio—whence emanated many of the errors and the final truth—another eel falling into initiated hands marked the crisis in the eel question. Among these privileged ones was the famous Galvani, and in grave council assembled, he agreed with the others that it was the counterpart of Vallisneri 's historic eel of seventy years before, and was a precious specimen and must be sent to the naturalist Mondini. And Mondini, in a publication which is classical, first described in accurate terms the female eel, and lifted the eel question out of the uncertain field of speculation to a basis of solid fact.
Not immediately, however. Spallanzani a few years after visited the Comacchio region for the sole purpose of studying eels and reported a negative to Mondini 's observations, which accordingly suffered a nearly total eclipse lasting many years. In 1850 Rathke was able to describe an eel in full roe, the first that ever came into the hands of an investigator, the eggs of Mondini's eel being immature. This important event was the final blow that settled the sex question as far as eels are concerned. Over twenty years afterward, however, the German Fishery Association in Berlin was led by renewed interest in eels, due to the stimulus of Syrski's work on the male eel, to offer a reward of fifty marks for an eel in full roe. The eel was to be submitted to Professor Virchow, and the royal superintendent of fisheries undertook to forward the responses. It seems that about every German newspaper 'from the Rhine to the Vistula and from the Alps to the sea,' gave publicity, with a result creditable to them, but overwhelming to the royal superintendent. His delight at the popular interest in eels was succeeded by astonishment and that by horror. His postal expenses compelled him to announce that all eels and communications should be forwarded direct to Virchow. The public complied and the great German savant was obliged to cry enough and beg for mercy. People wrote and sent their specimens, parts of eels, contents of eels, thread worms from eels and above all, stories of eels and of eggs in eels, but seldom an eel intact and none in the desired condition. They usually ate the eel and sent various and often irrelevant portions of its anatomy, with a request that the fifty marks be remitted by return mail. If this prize contest had no scientific results, it contributed to the merriment of the German nation. The comic papers cartooned the incidents and announced that in the future the scientists desired only smoked eels.
To Mondini is due the credit which has largely gone to Rathke of first demonstrating sex in eels. History repeated itself as often before and since in according the honors of priority elsewhere than they belonged. However, all these observers shared in determining an important and historic phase of the eel question, which, while there are still interesting queries connected with the natural history of eels, has now merged itself with the general and special problems of biology and is no longer paramount as in the olden days.
Eels themselves, as such, are no mystery, but a familiar and commonplace factor in our economy. From the epicurean standpoint extremes meet in them—they excite a gastronomic horror in minds appropriately constituted and a peculiar delectation in the gourmand in whom suggestion is not strong enough to appeal against the keen delight of a sensitive and discriminating palate. The eel has ever occupied an extreme position. He is apt to be loathed or loved. It is characteristic of him that he never did anything by halves. What he does he does with all his might. In breeding his offspring were legion and filled the seas. In his contact with the human race, he ingratiated himself into the affections of a whole nation, or was rejected utterly. The Greeks and Romans seem to be first in their regard for the eel, and many tales come down to us of the esteem in which he was held in their ancient times. The Romans cultivated eels, tamed them, made pets of them; and the orator, Hortensius, rival of Cicero, wept bitterly at the death of his favorite mursena. They even sacrificed their slaves to the eel ponds, a practice quite possible to men who plundered nature to serve peacocks' brains and parrots' tongues at their tables. The Egyptians are said by one account to have abhorred eels utterly, but it is certain that at one time eel-worship shows them to have also judged the eel to rank with the gods. The Scotch taboo the eel entirely, while the Hebrew race placed it under the ban which applies to scaleless creatures of the fish tribe. The conger eel is scaleless, but the common eel does not deserve this calumny, for its minute oblong scales, curiously arranged in groups instead of imbricated regularly as in the common fishes, are easily seen on careful inspection. The ancient Anglo-Saxon, on the other hand, was passionately fond of eels, which passed current as a medium of exchange. The race has always been partial to them and Londoners of to-day consume them in great quantities. Some ancient peoples used them in sacred offerings. Terracina, a seaport of Italy, being besieged by the Turks, the inhabitants vowed twenty thousand eels per annum to St. Benedict. The account relates that a 'fond memory of stewed eels' touched the saint and the siege was raised. He got his eels, and the Benedictine monks have been accustomed to render the yearly tribute to their saintly patron.
The prominence of eels among fishes is of course largely dependent upon their great abundance and almost world-wide distribution. Our common American eel is found from the Gulf of St. Lawrence to Mexico, but is absent from Hudson Bay and the Arctic Ocean and is present in the eastern Pacific only by transplantation at the hands of man. It inhabits both the sea and inland waters, but was unknown above the falls of Niagara until artificially introduced. Its natural history even yet is not as well known as would be expected. Most fishes which live alternately in fresh and salt water are anadromous, and feeling the sea their proper home migrate at certain seasons up the rivers, where they spawn in fresh waters and return to the salt until the next season. But the eel has been supposed to reverse this process, and, being at home in the sweet water, to descend to the sea to deposit the eggs, which are numbered in millions, and then die, its span of life naturally ended. The young eels resulting, driven by the impelling force of instinct, must then find their way back to the haunts of their parents. Well-known facts speak for this view. Young eels in the spring are known to ascend streams in countless numbers, and the phenomenon has long been well recognized as eel-fairs, or eel-fares. In some regions this is an event of the spring much looked forward to. The little eels are known as elvers—a corruption of eel-fare—and are boiled and pressed into cakes—eel-cakes—which become for the time being an important article of food.
Both elvers and adults, however, are found above obstructions in the rivers which seem to make impassable barriers. It is certain that the young display the greatest persistence in climbing streams, and evidence is not wanting that to get around obstacles they leave their native element and make a land journey. The stories on this point do violence even to the somewhat lax canons which by tradition and present practice are supposed to govern the history of the tribe of fishes. There is no doubt that they can wriggle for some distance over favorable ground, as through wet grass. Albertus Magnus writes in 1545: 'The eel also comes out of the water in the night time into the fields where he can find pease, beans, and lentils.' Another writer contradicts pointedly in differing from this opinion. He says: 'They eat fish, do not come on the land and do not eat pease, but remain in the water always and are nocturnal animals.' But Bach, a Prussian naturalist, insists that eels do devastate the pea patches and avows that the peasants fish for them with the plow by cutting a furrow before daybreak, which intercepts their retreat, and that sometimes for the same purpose sand or ashes are used, which adheres or dries the slime on their bodies, making locomotion impossible. On the other hand, it is related that eels stranded by the drying of pools adjacent to larger waters have not attempted the short journey necessary to return to the main stream, and that the presence of eels far overland is to be attributed to poachers who throw them away in flight from pursuit.
It is not to be doubted that the necessity of water breathing is no bar to short overland journeys. The moisture of the grass or ground which is a necessary condition of such wanderings probably replaces somewhat for breathing purposes the natural. medium which the eel leaves and to which his return can not be long delayed. Many fish can suspend respiration for quite a while without suffering injury. Concerning this habit a curious opinion is expressed by an English writer not so many years ago. He says, speaking of the eel, 'The curious airbladders, so-called—which are really intended as reservoirs for water to moisten the gills of the fish when traveling out of the water—have been held to prove that it is properly an air-breathing creature, which occasionally, like some snakes, sojourns in the water for reasons of its own.'
The eel seems to have taken its name, and in more languages than one, from its suggestion of the snake. The Anglo-Saxon aal is derived from the Finnish for slimy, while the scientific name is the Latin for snake, Anguilla. Many English names of places are compounded of eel—witness Elmore, Ellesmere, and Ely. Of the latter Fuller, in 'Worthies of Cambridgeshire,' has this illuminating explanation: "When the priests of this part of the country would still retain their wives in spite of whatever the pope and monks could do to the contrary, their wives and children were miraculously turned into eels, whence it had the name Ely. I consider this a lie." Like other objects of popular interest which include elements of mystery, eels are the subject of the most extravagant tales. Some of these are quite analogous to the threadbare story of the live frog found in the interior of a solid rock. A New England paper some years ago heralded that 'a live and active eel, a few days since, was dug out from a depth of five feet in the soil of Exeter, New Hampshire.' Doubtless this eel is exhumed annually. The tenacity of life of frogs and eels affords the starting point for these legends. Likewise to the voracity of eels may we credit an ancient chronicle that in England a few of them were one dark night observed to consume entirely a stack of hay. It may be in a spirit of emulation that some German carp—importation of the Government—artificially transplanted to the pond of a western farmer, came out one night and ate up the crop of buckwheat on a neighboring field. Elvers are reported to climb trees and the tale might not be incredible, provided any imaginable reason for such conduct could be assigned, for by their persistence they sometimes ascend the perpendicular barrier of a dam a short distance. This they accomplish by the partial drying of those that first essay the ascent, which therefore stick to the boards and afford a slight foothold for the next comers, which wriggle a little higher and then in turn stick fast and perish.
These stories might be multiplied ad nauseam, but more interesting are a few facts about the symbolic significance of the eel. His slipperiness long ago passed into a proverb. Among the pictorial writings of the Egyptians the representation of an eel held by the tail denoted 'a man vainly pursuing a fugitive object. 'A Greek expression of similar import reads, 'You've an eel by the tail.' It is not so well known that an eel figures also in an emblem of quite opposite meaning—certainty instead of uncertainty. It is quite impossible to hold one in any ordinary clutch of the hand. The intervention of a fig leaf, however, makes the grasp secure, and the Egyptians depicted an eel rolled up in a fig leaf when they wished to express certainty regarding things that were a priori uncertain.