outside to deposit the spawn. Or there may be a sort that never go as far east or west as the others, but winter along our shores," &c.; while Dr. Gilpin expressly remarks that though the asserted torpidity and blindness favor the idea of hibernation, he does not think that we have yet sufficient proof to assert them as facts.

The authorities quoted in support of the hibernation theory do not in fact support it, and the testimony cited by Professor Hind is merely tradition and popular opinion, some obtained directly, the remainder at second-hand.

(3.) Still another set of arguments is based upon the supposed hibernating habits of other species of fishes. Professor Hind remarks: "In seas which are not ice-encumbered the winter torpidity (of the mackerel) may be of very short duration; in ice-encumbered seas it may extend over several months. In this particular the mackerel resembles the sturgeon of the Caspian Sea, whose torpidity during winter is well known, and this winter sleep is not confined to these fish, but is probably much more general than is usually supposed."*

Here we have a definite statement. The mackerel hibernate, and the winter sleep is not confined to the mackerel.

The only hibernation which is definitely known to occur among fishes takes place in the fresh-water lakes and streams of cold regions. The fish are driven by cold into the deeper waters, and there remain in a state of torpor proportionate in degree to the amount of cold which they experience. They may even be frozen up in the midst of a mass of ice and recover their vitality when the ice is melted. †

In warm regions an analogous phenomenon takes place which has been called æstivation. When the lakes and streams are dried up by the heat the fish seek refuge in the deepest pools, and when these too are dry they bury themselves in the mud at the bottom and remain torpid until the rainy season refills the reservoirs and revives them.

Fishes in the extreme north doubtless undergo similar experiences, though I am not aware that any record of such a phenomenon has ever been published.

Hibernation and æstivation do not appear to be in any case voluntary acts. The fish do not become torpid of their own volition. They avoid it as long as they can, and only succumb when they are deprived of means of escape. They never become torpid when there are greater depths to which they can retreat. I

Part II, p. 11.

+ Mr. Milner had a mud-minnow (Umbra limi) which was frozen in solid ice in the middle of an aquarium globe three or four times, and each time recovered its vitality upon thawing out.

"A curious phenomenon in Indian fresh waters, and one which has never been satisfactorily explained, is the sudden appearance of healthy adult fishes after a heavy fall of rain, and in localities which for months previously had been dry. When pieces of water inhabited by fish yearly dry up, what becomes of them? On January 18, 1869, when examining this question, I was taken to a tank of perhaps an acre in extent, but

(4.) Professor Hind lays much stress upon the presence of a "film" over the eyes of the spring and autumn mackerel and upon their alleged capture in winter in the waters of the Dominion, and also quotes arguments for hibernation based upon the resemblance of the mackerel to the batrachians (which are known to be capable of hibernation) in color, and upon its resemblance to embryonic forms of other fishes which is supposed to "prove him low in the scale of intelligence."* To the latter it is needless to refer. The so-called "film" on the eye is not peculiar to the mackerel. Many fishes, such as the shad, the alewife, the menhaden, the bluefish, the mullet, the lake whitefish, and various cyprinoid fishes have a thick, rough membrane covering the anterior and posterior angles of the orbits narrowing the opening to the form of an ellipse with a vertical major axis. This possibly be comes somewhat more opaque in seasons of decreased activity. It which was then almost dry, having only about four inches of water in its center, while its circumference was sufficiently dried to walk upon. The soil was a thick and consistent bluish clay, from which, and not nearer than thirty paces to the water, five live fish were extracted from at least two feet below the surface of the mud. They consisted of two of Ophiocephalus punctatus and three of the Rhynchobdella aculeata. All were very lively and not in the slightest degree torpid. They were covered over with a thick adherent slime. Among the specimens of fish in the Calcutta museum is one of the Amphipnous cuchia, which was dug up some feet below the surface of the mud when sinking the foundation for a bridge. If when the water failed fish invariably died, the tank would be depopulated the succeeding year unless a fresh supply was obtained from some other source, while the distance from other pieces of water at which they reappear excludes, in many instances, the possibility of migration, which must always, to a certain extent, be regulated by distance, time, and other local circumstances. Some species, especially "compound breathers," are unable to live in liquid mud, which they cannot employ for purposes of aquatic respiration.

"The practical question is, whether, when food and water fail, some fish do not æstivate until the return of a more favorable season. Natives of India assert that they do thus become torpid in the mud. As the water in tanks becomes low, the fishes congregate together in holes and places in which some still remains, where they may be frequently seen in numbers huddled together with only sufficient water to cover their dorsal fins.

"If disturbed they dive down into the thick mud, so that a net is often found ineffectual to take them. The plan employed to capture them is for the fisherman to leave the net in the water, and to walk about in the surrounding thick mud; in time they come to the surface to breathe, and fall an easy prey.

"As the water gradually evaporates, the fishes become more and more sluggish, and finally there is every reason to believe that some at least bury themselves in the soft mud, and in a state of torpidity await the return of the yearly rains. In Ceylon, Mr. Whiting, the chief officer of the western province, informed Sir Emerson Tennent that he Ead accidentally been twice present when the villagers had been engaged in digging up fish. The ground was firm and hard, and "as the men flung out lumps of it with a spade, they fell to pieces, disclosing fish from 9 to 12 inches long, which were full-grown and healthy, and jumped on the bank when exposed to light. Many other animals which possess a higher vitality than fish æstivate during the hot months, as Batrachians, the Emys, the Lepidosiren annectens, and some of the crocodiles. Mollusks and land-snails are commonly found in this state during the hot and dry mouths. (Day's Freshwater Fish of India, p. 28.)

* Part I, p. 79.

never has been observed to cover the whole eye. Until the fact has been established that "a skin forms over the eye in winter" it is quite unnecessary to propose the theory that such a skin "is probably designed to protect that organ from the attacks of the numerous parasitical crustaceans and leeches which infest the external portions of the bodies of fishes, and are also found internally, as in the gills of codfish "*

Criticism of the argument based upon the presence of mackerel in northern waters late in the season.

A number of instances are cited to prove that the mackerel schools remain on the coast of the Dominion throughout the winter season. If this can be well established it is a very strong argument in favor of hibernation. Let us analyze the testimony.

Dr. Gilpin is quoted to the effect that during some seasons they linger on the Nova Scotian coast until December, and allusion is made to a mackerel obtained by him at Halifax, October 27, 1875.†

Mr. John Rice remembers that his father used often to speak of mackerel "coming on shore like squid with scales on their eyes and blind about Christmas," about 40 years ago.

Mr. Jabez Tilley states that they have been taken in November in Trinity Bay.

Professor Hind also states that they are to be found on the whole coast from Quirpon to Cape Spear during November and December. He gives no authority for this statement, and it is to be inferred that it is founded upon personal observation.

Then there is the vague statement of Mr. Ambrose, already quoted, that mackerel have been speared on muddy bottoms under the ice. Now this testimony does not, by any means, tend to prove that the mackerel remain near the coast in winter.

In the first place there is no satisfactory proof of their occurrence later than October 25, since that is the only evidence fortified by a memorandum of date, and the memories of fishermen are not more certain than those of other men.

In the second place it is not impossible that mackerel linger in these waters until November or even December in the case of a very warm autumn. The temperature necessary for the menhaden cannot be many degrees below 50°, while the mackerel appears to endure a temperature of 410 or less. Menhaden linger in Maine waters till November and in Massachusetts Bay and the Vineyard Sound till December. Finally, the undoubted capture of many individuals in winter on the coast of Newfoundland would by no means prove that the great schools were there throughout the season. Disabled, blind, or diseased individ

uals would naturally be unable to accompany the departing schools. Such fish would naturally grovel on the bottom in a helpless state and might easily become impaled on the eel-spears, or might be thrown on shore by the waves, as the Newfoundland fishermen relate. Even healthy fishes might occasionally be accidentally detained. Mr. Peter Sinclair a well-known fisherman of Gloucester, stated to Professor Baird that some years ago a school of mackerel were detained all winter in a small river in Nova Scotia, and were speared out of the mud. This is doubtless hearsay testimony and is given for what it is worth. I do not doubt that there have been individual cases of this kind, but I maintain that no generalization should be founded upon them.

The theory of extended migration discussed with reference to the habits of the mackerel.

88. The preceding paragraph is devoted to the refutation of the idea that sea-fish hibernate. This is regarded as the least probable of the three hypotheses stated in paragraph 85. In paragraph 84 it is stated that the sea-herring and many other fishes have two kinds of migra tions: one bathic, or from and toward the surface; the other littoral, or coastwise. Now, in some species the former is most extended; in others, the latter. The anadromous species very probably strike directly out to sea without coasting to any great degree, while others, of which the mackerel is a fair type, undoubtedly make extensive coastwise migrations, though their bathic migrations may, without any inconsistency, be quite as great as those of the species which range less.

Upon this point I cannot do better than to quote from a manuscript letter from Professor Baird to the Hon. Hamilton Fish, Secretary of State, dated July 21, 1873. Having expressed the views concerning the migration of the herring and shad already quoted in paragraph 84, he continues:

"The fish of the mackerel family form a marked exception to this rule. While the herring and shad generally swim low in the water, their presence being seldom indicated at the surface, the mackerel swim near the surface sometimes far out to sea, and their movements can be readily followed. The North American species consist of fish which as certainly, for the most part at least, have a migration along our coast northward in spring and south in autumn, as that of the ordinary pleasure-seekers, and their habit of schooling on the surface of the water enables us to determine this fact with great precision. * Whatever

may be the theories of others on the subject, the American mackerelfisher knows perfectly well that in the spring he will find the schools of mackerel off Cape Henry, and that he can follow them northward day by day as they move in countless myriads on to the coast of Maine and Nova Scotia."

It is difficult to estimate to what extent the advocates of the hibernation theory have been influenced by patriotic motives in their efforts

to prove that the mackerel remain in the waters of the Dominion of Canada throughout the entire year. It is certain that all recent treatises on ichthyology by Canadian writers have appeared in the form of campaign documents apparently intended to influence the decisions of diplo matic commissions.

I am by no means prepared to maintain that mackerel do not pass the winter in the American domain of Her Imperial Majesty. It seems important, however, that the subject of the migration of fishes should be restored to its proper position as a question of abstract scientific importance. Let us glance at the arguments of Mr. Whitcher and Professor Hind against what the former is pleased to style the "American theory."

In the report of the Minister of Marine and Fisheries for the year end. ing the 30th of June, 1871, Mr. W. F. Whitcher, Commissioner of Fisheries, published a paper entitled "American theory regarding the migration of the mackered refuted".*

Mr. Whitcher opens his letter by claiming that the theory of north and south migration was invented solely in support of a claim advanced by citizens of the United States to participate in the Canadian inshore fisheries. "This ingenious but traditional theory of annual migration having gained local credence among some of the Nova Scotian fishermen. engaged in United States fishing-vessels, has been sagaciously indorsed and circulated by American authors." He also refers to evidence "supposed to have been procured among the fishing population of the New England States."

I need only say that these claims are unjust, and that the theory of the annual north and south migration of the mackerel is time-honored, and was held conscientiously by ichthyologists of the United States and the provinces long before the question of fishery treaties assumed its present aspect. It is manifestly unfair to state that, while the theories which prevailed respecting the habits of herring and mackerel were formerly similar, that "in the former case it is probable that traditionary and imperfect information formed the basis of error, while in the latter instance it is most probably founded on misinformation dictated by sectional interests." Mr. Whitcher's own paper upon migration is the only one of American origin in which I have seen scientific method sacrificed to partisan spirit.

Having read Mr. Whitcher's introduction, one might readily predict what sort of an argument he will wrench out of the statements of "such disinterested authorities as may be readily quoted." First he gives extracts from Mitchell and the Edinburgh Encyclopædia regarding the habits of the herring. Granting all that is claimed about the herring, without reference to the liability of these authorities, what do we find? Merely a begging of the question. The habits of the herring and the mackerel are not known to be the same. In many particulars they are

* Pages 186-189.