as the conclusion would be, from the white of an egg being found in a single human stomach after breakfast, to conclude that the race lived solely upon eggs.

But to return to the roe-aals. These animals seem to be, if not the same, at least very nearly approaching to the identical food which, according to Dr Knox, gives the herring its value, and the Dutch their superiority in curing this fish. In a note to Lacepede's account of the herring, which is similar to that of Bloch, his ingenious editor adds an explanation in regard to what the roe-aal of the fishermen of Norway really are. I quote the passage.- -"These are not worms," says he, "but minute shrimps, which are found in the intestines of the herrings fished on the coasts of Norway. This species of crustacea, described by M. Fabricius under the name of Astacus harengum, and which the Norwegians call aal and sil aal, is so multiplied during summer, that thousands of these animals are found in a bucket of sea-water. They serve as the food of fishes, and principally of the herrings, which follow them wherever they direct their course, wherever the wind or current drives them. M. Stroem attributes to the eyes of these shrimps, which contain a deep red fluid, the reddish colour of the excrements of the herrings, a tint which is communicated even to the belly."-Sonnini's Buffon, vol. lxvii.,

p. 15.

Lacepede, in the same article, says that "the food of the herring, to which it owes its rich and agreeable taste, consists generally of ova of fishes, minute crabs, and worms.". Ibid.

M. Fabricius, the author alluded to in the foregoing extract, published his "Species Insectorum" in 1781. His character as a naturalist, and that in a department peculiarly his own, is of the very first order. The minute shrimps, which were ascertained to form a chief part of the food of the herring on the coasts of Norway, he thus describes :

"Astacus harengum, antennis posticis bifidis porrectis, rostro subulato, oculis globosis prominentibus. Habitat in Oceano Norwagico copiosissime, harengum et gadorum esca."-Vol. I. p. 511.

"Gammarus esca, manibus adac

tylis, cauda articulata subulata apice fissa. Habitat in Oceano Norwagico. Harengum cibus gratissimus."—Ibid. 518.

Here, I take leave to remark, are no doubtful conjectures upon a halfdigested animal of dubious identity; but scientific descriptions of the minute or microscopic shrimps upon which the herring was known to feed, enabling future observers to identify the species.

In almost all of the herring stomachs, now on the table, fragments of minute crustacea were found in considerable abundance. There were evidently more than one species.

Latreille, the most celebrated of modern entomologists, in his History of Insects, Paris, 1798, records the Gammarus esca of Fabricus as the food of the herring. The Astacus har engum of the same author he refers to a new genus, Mysis, and states that it has been found on the coast of France.

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In the Dictionnaire des Sciences Naturelles, and under the head Clupea, M. Hippolyte Cloquet says of the herring, "Il se nourrit d'œufs de poissons, de petits crabes, et de vers." (IX. 428.) And Bosc, in the " Nouveau Dictionnaire d'Histoire Naturelle," says, " Ils vivent de petits poissons, de petits crustaces, de vers marins, de mollusques, &c. et ils servent de nourriture à tous les cétacés, et à tous les poissons voraces qui habitent les mêmes mers qu'eux."-(XIV. 198.)

In Gmelin's edition of the Systema Nature of Linnæus, the translation of which, by Dr Turton, published in 1802, it was certainly in Dr Knox's power to have consulted, the Astacus harengum and Gammarus esca of Fabricius are mentioned as the food of the herring-the last species, indeed, "as the chief food of herrings."(III. 761.) And in the "British Zoology" of Pennant, not unknown to Dr Knox, if we may judge so from his referring to this work, that excellent naturalist says, regarding the food of the herring, "What their food is near the Pole, we are not yet informed; but in our seas they feed much on the Oniscus marinus, a crustaceous insect, and sometimes on their own fry. The herring will rise to a fly. Mr Low of Birsa, in the Orkneys, assures me that he has caught many thousands with a common trout-fly, in a deep hole in a rivulet into which the tide

flows. He commonly went at the fall of the tide. They were young fish, from six to eight inches in length."(Pennant, III. 448-9. Lond. 1812.)

The Reverend George Low, in his posthumous work, entitled Natural History of Orkney, published by Dr Leach in 1813, confirms this statement (p. 227); and Dr Macculloch corroborates these in a paper published in Brande's Journal of Science in 1823. "When they (the herrings) first arrive, and for the apparent purpose of spawning, they are not in shoals. They cannot be taken in nets from their dispersion. But the Highlanders then fish them with a feather or a fly, and a rod, and by this very amusing fishery, they take them in sufficient quantity to render it a profitable occupation; as one man has been thus known to take a barrel and a half, or about 1200 fish, during the few days this fishery lasts."-(XVI. 221.)

Dr Neill, in a List of the Fishes of the Forth, published in the Wernerian Transactions in 1811, states his having found" in the stomach and œsophagus of a large female herring no fewer than five young herrings (not sprats) the lower partly dissolved, the others entire.' And he adds, that when in Shetland in 1804, I met with people who had occasionally taken herrings when fishing for piltocks or coal-fish with limpet bait." (I. 545.) I myself once found in the stomach of a large herring two partially decayed young fishes of the same species. And there is now on the table (No. 6), a stomach of a herring taken this summer, containing a young animal of the same or some allied species.

Sir John Barrow, in the article Fisheries, printed in the Supplement to the Encyclopædia Britannica, gives it as the result of his enquiries that the herring "fattens on the swarms of shrimps and other marine insects" which abound in the Northern seas (IV. 257). And Mr Wm. Scoresby states the swarms of minute medusa which are found in these seas, and even colouring the water, as beyond calculation. The fin-whales and dolphins (says he) " feed principally on herrings, and other small fishes. These subsist on the smaller cancri, medusæ, and animalcules." (Arctic Regions, I. 546.) "Thus," continues

66

he, "the whole of the larger animals depend on those minute beings, which, until the year 1816, when I first entered on the examination of the seawater, were not, I believe, known to exist in the Polar seas. And thus we find a dependent chain of existence, one of the smaller links of which being destroyed, the whole might necessarily perish."-(I. 546.)

Dr Macculloch also states the minute meduse to form part of the food of the herring, on the coasts of Britain. "Among that food" (says he) "we may reckon the meduse, and other analogous marine vermes, which are produced in such abundance in all these shallow seas."-(Brande's Journal, XVI., London, 1823.) And in the volume of the same Journal for 1829, he remarks" If the stomachs of these fishes are widely examined, they will not be found empty, though we cannot detect organized forms in them, as we find entire crabs in the stomach of a cod-fish. Nor is this surprising, when we consider how small and how tender the tribes of marine worms and insects are, and how rapid is the digestive power of fishes."(Quart. Journal of Science, 1829, p. 134-5.)

I now come to the volume of the Highland Society Transactions for the year 1803, which is referred to by Dr Knox in support of his assertion that, prior to his assumed discovery in 1833, the food of the herring was totally unknown. Before stating what this volume contains on the subject, although including the opinion of a Professor of Natural History, I must take leave to state, that, supposing the authors of the papers in this valuable work to have decided that the food of the herring was to them totally unknown, yet this dictum, in place of proving the fact, would only have proved their ignorance of what had been previously written upon the subject. After what I have already stated as to the numerous authors who have mentioned and described the food of the herring-not even the opinion of Dr Knox, nor Professor Rennie of the King's College, London, celebrated as they are or may be, can weaken their testimony. They may choose to shut their eyes in sunshine and faney it to be dark. The only inference to be drawn from such state

ments is probative of the ignorance of those who make them.

Here I cannot help noticing the ignorance of the natural sciences which this volume indicates as prevailing even among well-informed men in other respects. There is more information regarding the natural history of the herring in the work of Neucrantz, published 150 years previously, than is to be found in these papers. And it is but justice to my learned friend, Professor Jameson, to say, that it is only since his appointment to the chair of natural history, and the establishment of the Edinburgh Museum, that that taste for the study of nature in this country has been excited, which has led to so many spendid additions to our knowledge.

The Rev. Dr Walker, in a paper on the natural history of the herring, in vol. ii. of the work referred to, and whom Dr Knox characterises as a "strictly correct, scientific, and candid person," observes that "he had examined the stomachs of herrings at different seasons of the year without finding in them any sort of palpable aliment." (P. 274.) "On their first appearance off the Lewis, in the month of July, when they were full grown, and very fat, nothing appeared in their stomach but a little slime."—(P. 275.) " During the residence of the herrings on the coast of Scotland, we know of no food they use, and it is probable they require little or none, except some attenuated alimentary matter which the sea-water may afford them."-(P. 275.) "We think it not altogether improbable that they may live on a small species of medusa, or some similar marine animal, which is not as yet known to naturalists."-(P. 276.)

Here Dr Knox confines himself, in the quotations he gives from Dr Walker's paper, to extracting such sentences as imply the food of the herring to be totally unknown. But this is not the way, were the matter at all doubtful, to arrive at a just conclusion. I shall give the sequel of the passage in Dr Walker's words:

"In the ocean, to the north-west, and at a considerable distance from the most northern extremity of the British islands, a vast profusion of a singular substance has been often seen floating on the surface, and that by skilful mariners, who were also conversant with the herring-fishery. The different

accounts given to me by these persons agreed in this, that the substance consists of separate globules of a roundish figure, and of the size of a pea, resembles blubber, covers the surface of the sea to a great extent, and makes it to appearance as if covered with oil; that the herrings are known to feed upon it; and that it has been observed in great profusion to the north-west of Shetland, where the herring shoals existed at the time, but has nowhere else been seen on the coast of Scotland. If this account, given by persons of observation and veracity, is admitted, we need be no longer surprised at the retreat of the herrings to those tracts of the northern sea, nor at their return from thence in a full-fed and fat condition. The substance here intimated is probably a small species of the medusa, or some similar marine animal, which is as yet not known to naturalists."-(II. 275, 276.)

Dr Walker seems perfectly right in his conjecture; for Mr Scoresby and Dr Macculloch, as has been already remarked, positively mention species of medusa as the food of the herring. The former states their incalculable numbers in the Northern seas, tinging the water for miles, and gives figures of several species; and the latter states that he has seen large tracts of the Cornish coast, where the "whole sea was almost a mass of life, from the presence of these and other marine animals."-(Jour. of Science for 1830, 135.)

p.

In the same volume is a paper, by Mr John Mackenzie, on the fisheries of Scotland, which tends to corroborate the fact of some minute species of medusa forming the food of the herring in certain situations. "Another article of their food" (says he) "is an oozy substance at the bottom of the sca, adapted, it would appear, by the Author of Nature for that purpose. This sometimes appears in calm weather floating on the surface, in the form of small globules, at which fishermen have observed herrings to spring as trouts do at flies."-(P. 314.) These floating globules were, there is little doubt, some small species of medusa, or kindred animal, such as referred to by Dr Walker, and mentioned as the food of the herring by Mr Scoresby and Dr Macculloch; and goes to prove, in addition to what is stated by these writers, that minute molluscous ani

mals form an important portion of the food of the herring in particular sea

sons.

A stomach of a herring, caught in the Frith of Forth this summer (1837), containing this species of food, is on the table, No. 7.

Mr Mackenzie further states, that, "in regard to the food of the herring, it has been frequently observed that the small fry suck their nutrition out of the marine alga, or from some matter adhering to them." This observation is borne out by the fact of many marine animals depositing their ova on the sea-weed, and by the fact of ova of fishes, and even those of their own species, being found in the stomach of the herring. Mr Mackenzie also mentions that "it has been ascertained by fishermen that herrings will swallow a clear unbaited hook, such as is used for catching haddocks, when tied to a fine line; a device which has been often successfully adopted when the herring fishery is carried on in deep water, in order to discover the arrival of the shoals. It seems certain, therefore, that the herrings take these hooks for such animalcules as they, at least, sometimes feed upon."-(II. 313, 314.)

In the same volume is a paper, by the Rev. James Headrick, on the fisheries of Scotland, which Dr Knox has also quoted as proving the food of the herring to be unknown. But, as the Doctor has only given a portion of the paragraph on the subject, and founded on it as a distinct proposition, it is necessary to give the whole statement in connexion. "With regard to their mode of feeding," says Mr Headrick, "it is, in all probability, similar in the salmon and the herring. I suppose they live chiefly on water, and on small insects which abound both in the sea and in rivers. I have been told of the fry of smaller fishes found in the stomachs of salmon; but such instances never occurred to me, and I never heard of any animal being found in the stomach of a herring."

Here Dr Knox's quotation stops, lest the explanation which follows might lessen the value of his assumed discovery. But Mr Headrick continues thus: "This," says he, "may be owing to the strong digestive powers, which speedily convert into chyle the food received into the stomach. In all the experiments I have heard narrated, with a view to ascertain on what the herring feeds, it appeared that a considerable time was allowed to elapse between its being killed and cut up. Now, such an experiment is not fair. In man and other animals the power of the gastric juice is known to continue after death, so as not only to liquify the contents of the stomach, but even to corrode the stomach itself. The only way to know on what a herring feeds, is to cut it up immediately after it has enjoyed a full meal. Both the salmon and the herring leap at flies and other winged insects. Trans. High. Soc. II. 444, 445.

In regard to what is stated by Dr Walker and Mr Headrick as their own opinion, that opinion is corroborative of what had been before discovered as to the food of the herring. As to their ignorance of what had been previously observed and recorded upon this subject, I cannot pretend to account. But their want of knowledge by no means proves, in the face of evidence to the contrary, that such knowledge did not exist. I am aware that, from the interruption of intercourse occasioned by the wars of the French Revolution, there was difficulty in getting books from the Continent; and a great degree of ignorance seems to have prevailed in Scotland as to the progress of the natural sciences in foreign countries, and even in England. But for Dr Knox and Professor Rennie there is not the same excuse; and the only conclusion that can be drawn from the statements of these gentlemen is, that when they penned them they were not aware of what had been previously written.

I now come to the third point, on which I have to make a few observations, tending to show that the food of the salmon was perfectly well known to Naturalists before the publication

of Dr Knox's paper. Dr Knox's assertions, however, are as confidently made with regard to his discovery of the food of the salmon, as they were with regard to the food of the herring,

and, as I shall endeavour to show, equally unfounded.

"The nature of the food of the herring, Coregonus, and salmon" (says he)," was not to be stumbled on by accident. I feel happy in having to offer it as a direct result of patient scientific enquiry."-(P. 463.)

"As a proof of the difficulty of the enquiry, it being unnecessary to cite more here, I shall content myself with quoting a passage from a very recent work (1833) on natural history. The Complete Angler of Izaak Waltonedited by Mr Rennie, Professor of Zoology, King's College, London. In 1653, Walton found nothing in the stomach of the Fordige trout; and in a note, in the year 1833, Mr Rennie adds, "The same is true of the salmon, which has never any thing besides a yellow fluid in his stomach when caught."-(P. 467.)

The true salmon prefers a peculiar kind of food, the ova of the Echinodermata, and takes with great reluctance any other."

"When the salmon first takes to the estuary and to the river, whether beyond or within the influence of the tide, he does not feed, unless the estuary should happen to contain this peculiar kind of food."-(P. 468.)

"I have opened the stomach of a fish killed by the poacher in the month of October, nearly 100 miles from the ocean, with the peculiar food, and none else, in the intestines."(P. 470.)

This peculiar food-on reading the first part of his paper, Dr Knox restricted to the ova of the ECHINODERMATA, and nothing else.

The genera of the first order of this class are ASTERIAS, ENCRINUS, ECHINUS of Linnæus, and HOLOTHURIA. But only one species of the first genus, Asterias glacialis, is particularly mentioned as affording this food; and we are not informed how the ova of this genus, when separated from the animal, is to be distinguished from that of the other genera of the order. It would be information, indeed, to learn that Encrini were so abundant on our coasts, that their spawn afforded the salmon its peculiar food. On reading the second portion, he added another article to the salmon's bill of fare in "some of the crustacea." But in the abstract drawn up by himself, the food is limited to the Echinoder mata, as if these animals deposited

their spawn at all seasons, and in sufficient quantity, to feed the family of British salmon. There is not a doubt, that if Dr Knox had examined the stomachs of salmon at different periods, and on different stations, he would not only have found the ova of the starfish (for that is the only echinodermatous animal stated as supplying the peculiar food), but also the starfish itself, the smaller crustacea, and the small fishes which abound on the coasts which salmon frequent. But of this afterwards.

In the years 1824 and 1825, a Committee of the House of Commons was appointed to investigate the modes of carrying on the principal salmon fisheries in the kingdom, for the purpose of framing an Act of Parliament that should regulate that fishery, for the advantage of the river and coast proprietors and the public. A valuable body of evidence was thus procured regarding the habits of the salmon ; the period of its ascending the different rivers for the purpose of spawning; the deposition of the ova in the spawning beds; the descent of the young to the sea; and the food of this fish both in the sea and in rivers, &c. But though this enquiry was made with great ability on the part of the committee, and although the witnesses examined included practical fishermen, tacksmen of fisheries, river and shore proprietors, and scientific men of the first eminence, Dr Knox, upon what principle it is difficult to conceive, characterises the results of the whole minutes of evidence as "below critieism" (P. 500);" the persons offering the testimony and evidence, without any exception, incompetent to the task, the greater part being the evidence of individuals, to whom it would be impossible even to explain the care and precision and extent of direct evidence, requisite to arrive at a correct scientific conclusion"-(P. 500); and "none was found, throughout their most extended inquiry, who could offer a rational conjecture (founded on facts) personally known and understood (the result of positive research, by a competent naturalist and physiologist), as to the food of the salmon, its habitat while in the ocean, and its feeding ground."-(P. 496.)-The whole, in short, is " an inextricable mass of confusion and error."-(P. 463.)