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instance he mentions, says, that a pair and over all the rivers of the em. of salmon were observed in the White pire. tader, one of the tributaries of the The mode in which the salmon deTweed, to be spawning on Nov. 2. posit their ova in the gravelly bottom
The ova remains in the spawning- of shallow streams, is minutely describbed or gravel for three or four months, ed by Mr George Little (Report, p. according to Dr Fleming ; according 108-9), and, indeed, has been known to Mr John Johnstone, from the ova for centuries ; for John Monipennie deposited in November, December, has so long ago graphically recorded and January, the young rise from the the manner in which this instinctive gravel in March, April, and May; work is done. “ In harvest,” says he, according to Mr John Halliday, the " they come from the seas up in small spawn deposited in November, De- rivers, where the waters are most cember, and the beginning of January, shallow, and there the male and feis disengaged from the spawning-beds male, rubbing their bellies or wombs from Joth March to 10th April ; so one against the other, they shed their that it appears, on an average of sea- spawne, which forthwith they cover sons, the salmon roe lies about four with sand and gravel, and so depart months, or 120 days, in the gravel beds away.”—P. 195. before the young appear. But accord. As to the developement of the ova ing to Dr Knox, in his single observa- under Dr Knox's “ own immediate tion of the Whittader pair of salmon, personal observation," though the the ova took 142 days “to become ova would not, it appears, bear transfishes somewhat less than an inch in mission to Edinburgh-it really seems length,” but still “ embedded in the unnecessary to notice such an evidentgravel."'-(P. 473.) On the 19th of ly imperfect experiment, particularly April the fry are “eight and even since a very full and interesting acnine inches long ;' and on the 2d May count of the gradual developement of they still abound in the tributary the ova of the salmon, accompanied by streams, but are not so numerous as an accurate engraving, is given in the before ; they are not increased in size, evidence of a gentleman before the and are, in all probability, the fry of Parliamentary committee. To that a later deposit."-(P. 473.) So that engraving, and the description of the amount of Dr Knox's information the report in general, I beg to refer here is, that the spawn of a single pair any one who takes an interest in the was hatched in April, and other fami. subject. At the same time it is proper lies of other fishes were of a later de to mention, that there is an interesting posit, and appeared in May. The article on the “ Spawn of Salmon," witnesses examined before the Com- by Mr Schonberg, printed in Sir mittee of the House of Commons had David Brewster's Journal of Science stated all this much more fully in 1824 in 1826, accompanied also by an enand 1825. Thus, Sir Henry Fane says graving of the ova in different stages the fry descend in April and May- of growth. Both these sets of figures, Alexander Fraser, early in April and and the accompanying details, corresMay- Rev. Dr Fleming, March, April, pond with one another in every essenand May— Mr George Hogarth, jun., tial particular; but both at the same April and May-Mr William Stephen, time differ widely from the details March and April, to 14th May, ac- given by Dr Knox. Neither does the cording to the temperature of the sea- Doctor even hint in his paper at the son and the situation of the different existence of such details or tigures, rivers. It appears, therefore, that Dr though he could scarcely be ignorant Knox's single observation is corrobo- of what is stated in the Report, wbich, rative of the evidence led before the he asserts, he had repeatedly read over. Committee, as far as a single instance To pass over discrepancies which in a single river can ; only it is to be materially lessen the value of his reobserved, that he makes his single ob- marks, Dr Knox asserts, that “ ova servation, made he says by himself, taken from the bed of a river at any the rule for spawning in all rivers by time from January to March inclu. all salmon, without reference to sea. sive, and not shaken or carried far, son or situation ; while the evidence will live and become developed, i. e. of practical men give the average re- grow to fish of about an inch in length sult of many years of observation, ex- in a small glass full of water, changed jended over every variety of season, not oftener than once a week,” p. 476. Then follows a passage in which tity of trout in rivers or lakes." temperature is said to have some effect (Salmonia, p. 82). " In all experiin hastening or retarding the deve. ments of this kind" (continues Sir lopement of the ova, though in his Humphry) « the great principle is, reckoning by days such agency is to have a constant current of fresh and necessarily excluded; and he adds, aërated water running over the eggs. that “ after having cast the slough, The uniform supply of air to the fætus they will live about ten days (seldom in the egg is essential to life and or never longer) in water unchanged, growth ; and such eggs as are not apparently thriving, growing, and supplied with water saturated with darkening in colour (if exposed to the air are unproductive."-Salmonia, light) every day."-P. 477.
p. 82, 83. This assertion, of the ova and This necessary aëration, and exsalmon fry living a week and even ten posure to the influence of the sun's days in a small glass of unchanged rays, explains at once why salmon water (almost the only original obser- seek the gravelly bottom of shallow vation in the paper) is in complete streams for the purpose of spawning ; contradiction to all experiments that and the same instinctive impulse which have been made on the developement guides the salmon, induces the herring of the ova of this genus of fishes and the cod, among numerous other “ It is said by Sir H. Davy” (says Dr fishes, to approach banks and shores, Knox), “on the authority of a person of and thus carry boundless provision to the name of Jacobi, whose writings countless animals. It was a curious I have not met with, that the ova of circumstance in Jacobi's experiments, salmon are deposited in the gravel of that the effect of bis impregnation of rivers under streams, in order that the ova with the milt, often produced they may be perfectly aërated, or ex- in the trout monsters with two heads, posed to water which is so. This &c.-so different are the rude attempts reason, which appears so plausible, is of man from the instinctive workings probably not the true one."-(P.476). of nature. The person of the name of Jacobi here T he experiments on the salmon ova mentioned, though unknown to Dr by Mr Hogarth and Mr Schonberg, Knox by his writings, was a Counsel- who both traced their developement, lor of State to the King of Prussia, and from the first appearance of life, till a well-known experimenter on the the animal was an inch in length, artificial fecundation of the ova of further demonstrate the necessity of fishes. His experiments appeared in this aëration. With “frequent changes the Berlin Transactions for 1765, and of water, Mr Hogarth succeeded in have been referred to with approba- hatching the ova, and by changtion by almost every writer on the ing the water frequently' the ani. subject of fishes since. These expe- mals appeared vigorous for three riments were made chiefly upon the weeks, . after which they became restova of the genus Salmo; and he found less and uneasy.' (P.92). Mr Hogarth that by expressing the unimpregnated also tried one of the fry hatched in ova in water, and afterwards applying fresh water, if it would live in salt the milt, the ova became impregnated, water; but found that it immediately and went through the usual develope- showed symptoms of uneasiness, and ment. In making these experiments, died in a few hours."" (P. 92). The one thing essential to their success figures of the ova, and the young aniwas found to be necessary, and this mal in its different states, were drawn was the frequent, almost incessant, by an artist, at the request of Mr changing of the water; and hence he Hogarth, and an engraving of them is justly concluded, that the aëration of appended to the Report of the Comthe water where ova are deposited, is mittee on the Salmon Fisheries. necessary to the developement of the Mr Schonberg found the frequent ova. Sir Humphry Davy, notwith- change of water equally indispensable. standing Dr Knox's gratuitous as- “ Changing of the water" (says he), sumption of his incompetency to make “and if possible from the same river, observations on the generation of the must be repeated hourly, and they salmon, “ had this experiment tried must likewise be exposed to the sun's twice, and with perfect success; and influence.” (Journal of Science, v. it offers" (he adds) " a very good mode 238). The developement of the ova of increasing to any extent the quan- is well represented in the engraving which accompanies Mr Schonberg's whether we have an early spring or valuable paper. The details of his rot; sometimes there may be two or experiments are more extended than three weeks of difference, according to those of Mr Hogarth ; but both agree the season." “ I have observed, when in all the more important points. we have early warm weather, the fry
Dr Knox's experiment, although come early, and when we have a late said to have been made under his own spring, it is later before the fry rise eye, is contradictory of the fact that from the gravel bed." (P. 109). aëration of the water is necessary, as The descent of the fry to the ocean he, or the person who took charge for is, in the Avon, according to Sir Henry him, appears to have kept the try in Fane, in April and May--in the water unchanged. But better evi- Ness, according to Alexander Fraser, dence than this will require to be pro- early in April and May—in the Don, duced before we can give up the March and April, to the middle of hourly and daily observations, bearing May-in the Dee, April and Mayall the marks of truth, made by Mr in the Tay, March, April, and May ; Hogarth and Mr Schonberg, in oppo- and so on, according to the season. sition to the statements and examina- The kelts, or spawned fish, descend tions of Dr Knox or his assistants. Of with the winter and spring floods. But Dr Knox's candour and fairness in not the dates given in evidence by the referring to the experiments of those numerous and respectable witnesses gentlemen, though one of them ap- examined before the committee are peared in the Parliamentary Report not be taken as absolute periods, which he so much abuses, and the common to every year. The tempeother in a Journal consulted by every rature of the season must be a powerone with any pretensions to science, I ful element in determining the ascent leave others to draw the inferences of the salmon, the deposition of the limiting myself to the plain statement ova, and the hatching of the ova; in of facts. Of course I hold, with all fact, the temperature and other cir. writers on the subject, except the cumstances, there is every reason to author of this memoir, that the aëra- believe, might have the effect of hastention of the ova by the frequent change ing or delaying the process of reproof water is necessary to the develope- duction, as the same meteorological ment of the salmon fry in rivers ; and agents are known to hasten or retard that this, and a certain exposure to the annual harvest, or prematurely the rays of the sun, influence the ap. bring out or delay the appearance of proach of fishes to the banks and shores many of the insect tribes. With the upon which they deposit their spawn. exception of Dr Knox fixing a deter
In reference to Jacobi's experi. minate period for the developement of ments, the stocking of ponds or lakes the ova in the gravel till the appearwith any desired species of fresh-water ance of the smolt, I say, with this exfishes, is, by these experiments, proved ception alone, any reader of his paper, to be comparatively easy ; for he and the minutes of evidence, might found that the ova could be impreg. have naturally enough supposed, that, nated, and the animals from these with regard to these points, he took ova hatched, after the parent fishes his information from the Parliament. had been dead four days. Even the ary Report, which he reprobates, and Vendace of Lochmaben might thus be from the testimony of witnesses whom introduced into other lakes without he declares unworthy of all belief; much danger of failure, by catching a and the strong coincidence between few of these fishes previous to spawn. the Doctor's periods of migration as ing. It is well known that the Chi. related in the Transactions, and what nese stock ponds with impregnated was stated by these gentlemen six spawn of fishes.
years before, must either appear very The period of the salmon fry rising strange, or the witnesses have not defrom their gravelly bed has been served that unmannerly abuse which already stated generally as occurring has been dealt out to them under the in March, April, and part of May; sanction of the Royal Society of Edinbut this of course depends upon the burgh. season. Mr George Little gives de- Another particular noticed by Dr cided evidence as to this point. “A Knox in his observations upon the great deal” (says he) “ depends upon salmon smolts is, that they will not the season at the time of the year, “ bear the slightest handling-they constantly died in a short time after of them returned to the river, and being touched."-(P. 481.)- And were caught, no doubt could remain as then the Doctor expresses his “surprise to their being of the number so markwhen" (says he) - we read of smolts ed. Two of these smolts, then be. caught" (it is not said how, but it mat- come grilses, I caught in six or seven ters not), “and after being, according weeks after they had been marked, to all accounts, rather roughly handled, when they weighed about 3 lbs. and even mutilated by the amputation each. In the month of April, 1795, of a fin, replaced in water, and arriv- I caught another of the number, then ing at mature years as a full grown a salmon, whieh weigned between 7 salmon ; we are, we repeat” (continues and 8 lbs. ; and in the month of Authe Doctor), “ left in wonder at the gust of the same year I canght a amazing contradictions between such fourth, weighing 8 lbs."— P. 391. observations and those we have per. But in case the author of the paper sonally made, observing every possible may object, that all these experiments care."-(P. 482.)
were made and related by men not This passage only proves Dr Knox's known to the world as scientific, I shall awkwardness, or the deadly nature of add to their testimony that of an illushis gripe ; for no one point in the trious naturalist, Lacepede, who, in natural history of the salmon is better stating the curious fact of salmon asascertained than that they survive the cending the particular rivers in which mutilation of a fin, and even live years they were hatched, thus writes: “ It with a ring round their body, close to is worthy of remark" (says he) “ that the tail. Thus Mr William Stephen Salmon return every year to the place says in evidence, " we have marked where they were spawned, as swallows fry going down, and have got them return to the buildings where they forthat season as grilses, and in the follow- merly had their nests. The physician ing season we have got them as sal. Deslandes bought twelve salmon at mon."-Report, 1828. Mr George Chautelain, a small town upon our Hogarth marked a number of smolts coast, near to which they capture to the in the month of May, by cutting off amount of 4000 salmon per annum. the mort fin; in the course of the He attached a ring of copper to the month of June, several of these, grilses, tail of these salmon, and then restored were found without that fin; in this them to liberty. Five of these fishes year (1825) there have been already were retaken the following year, three got three salmon marked in the same the second year, and three others in the way.--Report, 1825, p. 92. And Mr third." -Lacep. Son. Buff. xii. 133. Murdoch Mackenzie marked a grilse kelt in the month of March, 1823, in The history of the salmon, as dethe river Oykell, by tying a piece of tailed in the evidence before Parliawire round the body of the fish, im ment, and by writers on natural his. mediately above the tail; and in March, tory, may be told in a few words. 1824, the same fish was caught as a Impelled by instinct to ascend the salmon in the same river.-(Report, various rivers for the purpose of 1825.) But these experiments were spawning, at a certain period of the made by the provoking people who year, they reach the remotest streamhave forestalled all the Doctor's dis lets, where their ova may be deposited coveries, and anticipated him in every in safety, and the young, when hatched, point of the salmon's history, and who find their food. When this purpose are, therefore, on that very account, is accomplished, they return again to unworthy of belief.
the sea.* The same instinct guides A still more particular experiment the fry, when of a certain age, to fall is, however, related in the Highland down their native streams to the disSociety Transactions, Vol. ii., by Mr tant ocean, there to remain till the Alexander Morrison, « In May, 1794" imperative call of nature for reproduc. (says Mr Morrison), “I marked five tion impels them to seek again the smolts in the presence of five fishermen, places of their birth. It is not ascerand in such a manner, that if ever any tained satisfactorily whether salmon
* From experiments now in progress by Mr Shaw, Dumfries-shire, he is led to believe that the salmon fry do not leave the rivers or descend to the sea int the year in which they are hatched. Mr Shaw is even inclined to believe that they remain two years in fresh water before descending to the ocean.
ever ascend rivers beyond the tideway against all opposition, that preserves for any other purpose than that of the present supply. Were not the salspawning. The practical inference to mon one of the most prolific of fishes, be drawn from such facts is, that the its fishery on our coasts would soon fishery of salmon should cease, and the cease to be of value. animals be protected while spawning As not at all connected with the or seeking the spawning-bed. But as subject of these observations, I pass this period varies with the seasons, and over the uncalled for attack upon Dr the situation of the different rivers, Paley and our celebrated associate Sir and as, moreover, all the species de Charles Bell, in page 499. I only renot come into full roe at the same time, mark, that, in Dr Knox's paper, the the close time, so far as legislative reader will in vain look for inferences, enactments can do so, must be regu- drawn from the circumstances detail. lated by periods fixed arbitrarily on ed, of the wisdom and beneficence of the knowledge of the general habits that Great Being, who directs the miof the salmon, when the greatest num. grations of fishes, and teaches them, bers are observed to ascend the rivers, with unerring aim, to deposit their and the greatest number of spawned ova where the young, when hatched, salmon and smolts descend to the sea. are sure to find a supply of food. To prohibit the fishery in every month in which salmon are observed to as I have, I trust, satisfactorily decend and descend, would narrow the monstrated, that the food of the her. period of fishery without perhaps any ring and salmon was known and deequivalent advantage. The general scribed long before the appearance of migration of the mass, it is evident, Dr Knox's paper in the Transactions ought alone to regulate this close time; of this Society : That the food of the and there is full and satisfactory in- herring, in the first place, was well formation as to these periods, in the known and described by Neucrantz, evidence led before the Parliamentary by Leuwenhoek, by Müller, by FaCommittee in 1824 and 1825. Pro- bricius, by Bloch, and mentioned by tection in the rivers for the ascending Lacepede, .by Bosc, Latreille, Penfish, and till they have spawned and nant, Turton, Scoresby, MacCulloch, returned to the sea, is absolutely ne- and many others-indeed by almost cessary to insure the deposition of a every person who has written upon sufficient quantity of the spawn; and the natural history of the herring. this protection secured, there is no And that, in the second place, the food fear of an abundant supply. The na- of the salmon, in rivers and in the sea, tural increase of the salmon, did not its periodical ascent of rivers for the human ingenuity limit that increase purpose of depositing its spawn, the by the destruction in every shape of developement of the ova, and the dethe spawning fish that ascend the mi- scent of the fry to the sea, were all nutest streams, is quite equal to sup perfectly well known, in every parti. port the devastations which may be cular, before the year 1833, is equally committed on their ova or fry by ene- manifest, from the facts and authori. mies in their own element. According ties I have mentioned. to Mr George Little, there are in a I trust I have not, in attempting to salmon 17,000 ova, and in a grilse do justice to the claims of the illustri10,500 at an average ; and, according ous men who have written upon this to Bosc, 27,850 ova have been found subject, and in my remarks on Dr in a salmon of 20 lbs. weight. Even Knox's paper, gone beyond the limits the angler, under certain restrictions, of fair criticism. I should be sorry, would not be able materially to abridge indeed, if I was considered to have the number of the young, produced, as failed in the courtesy due by one memthey would be, if the spawning fish ber of this Society to another. But were protected, in myriads, and waft. there were statements which, in treated to the ocean in shoals which might ing of the subject, I was bound to confeed a whole people. It is only the tradict-there were claims of discovery wholesale destruction of the adult sal to be disproved by the statement of mon, when ready to spawn, and when prior discoveries—and if the author of it ascends the rivers for this purpose, the Memoir has appeared to disadvanthat obstructs the habitual fecundity tage in the comparison of rights, it of nature; and it is only the uncon- was a situation of bis own choosing. trollable impulse of instinct, acting