Popular Science Monthly/Volume 4/April 1874/Correspondence

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CORRESPONDENCE.



NOTE ON THE BREEDING HABITS OP THE MUD-MINNOW.

OUR very common "mud-minnow" (Melanura limi, Agassiz—Silliman's American Journal of Science, 1853, vol. xvi., p. 135), which is found over a wide extent of territory in America, and which, according to Dr. Albert Günther ("Catalogue of Fishes," in the British Museum, vol. vi., p. 231), is generically the same as the Umbra crameri of Europe, presents some features in its breeding habits which we have thought of particular interest, and would be greatly pleased to know if the European Umbra crameri, which Dr. Günther states inhabits the "stagnant waters of Austria and Hungary—neighborhood of Odessa," has identical habits; or, if the difference of climate, and character of the surroundings generally, have caused a more or less noticeable variation in its habits, especially during the spawning-season. We have not access to any work, on the fishes of Central Europe, that gives any details of their habits.

As we have already described it (American Naturalist, vol. iv., pp. 107, 388, Fig. 86), this little umbra is, "pure and simple," a mud-loving fish, and more strictly so than any other, unless we may except the eel (Anguilla acutirostris). During the present winter we have had unusually favorable opportunities for studying the fish during this part of the year. In December, while the weather was cool rather than cold, with but little ice, we found that hundreds of these fish were being thrown out with the mud then being scooped from the ditches of the tract of meadow on the writer's farm. On learning this, we had the mud carefully taken out by shovelfuls and examined, to learn the exact condition and position of these fish. They were, when taken from the mud, motionless, stiff, and apparently frozen; they were not brittle, and an attempt to bend or break them resulted in a very prompt but partial restoration of vitality (or consciousness?). Specimens thus roughly handled were permanently injured by being bent, even if not in excess of a degree of curvature that they can and do readily assume when in their normal condition. On placing specimens freed from mud in water of a temperature of 60° Fahr., which is pretty nearly or quite that of the ditch-water in summer, they only fully revived after lying on their sides, at the bottom of the vessel, for from twenty-five to forty minutes, and seemed to be injured permanently by the sudden change; but, if placed, with the mud still adhering to them, in water at a temperature of 40° Fahr., which became gradually warmer, by the vessel containing the fish being removed to a warm room, the minnows would become wholly themselves again, in from ten to fifteen minutes, and swim off in full vigor, as the mud slowly loosened from them and settled to the bottom of the vessel. As taken from the bottom of the ditch, the mud in which these minnows were hibernating was of about the consistency of cheese. As far as we were able to determine, these fish had burrowed tail-foremost, to a depth of from four to nine inches, and, in every instance, we believe the tail was deeper than the head, the position varying from almost horizontal to nearly or quite perpendicular.

Pursuing the investigation somewhat further, we found that, where these fishes had gone into winter-quarters in deep water, i. e., from three to five feet deep, the hibernating slumber was not as profound; and, when they were placed in clear water, at a temperature of 46° Fahr., they almost immediately swam about; slowly at first, but with steadily-increasing activity, and, in from three to five minutes, were in full possession of all their powers, and assumed the statue-like positions common to them, when seen in summer, when, for many minutes together, they will remain immovable, and only move when the near approach of an insect larva offers them a sure chance for a meal, or portion of one. It should be here mentioned that the water in the ditches from which we first gathered specimens varied from nine to fifteen inches in depth, and was coated with ice one inch thick.

During the past month (February), the weather being most of the time mild and spring-like––the smaller frogs singing throughout the day—we watched for the first appearance of these mud-minnows, and saw them in scanty numbers, first, on Sunday, the 15th. A week later (Monday, 23d), we found but few specimens in the muddy ditches, but a vast number of females, with distended abdomens, heavy with orange-colored masses of ripe (?) ova, in the swift, clear, ice-cold waters of the hill-side brooks.

On the 25th there was a violent snowstorm, with cold northeast winds, but this did not deter the "onward" movement of the minnows. Of the specimens taken from the rivulets, at this time, none were males, and it seems probable, although we could not positively ascertain the truth, that the male fish follow the females, and either seek out the deposited ova and fertilize it (does this ever happen?), or that the females wait until the arrival of the males before depositing their eggs.

We would refer, in conclusion, to one feature of their habits again. These fish, at the commencement of winter, by burrowing deeply in the mud of the waters they frequent, avoid the decided lowering of the temperature, which they, at this season, seem unable to withstand; but, at the approach of spring, they arrive, synchronously with the maturing of the ova in the females, and milt in the males, and, after thus recovering their wonted activity—say in February—no amount of severe weather deters them from seeking out exceptionally cold waters for their spawning-beds. This was shown by the late snow-storm above referred to, after which the female minnows were still found passing up the brooks, forcing their way up miniature cascades, with all the agility of a salmon, leaping from eddy to eddy, seeking out the most distant points from their muddy summer haunts that they could reach; and here, where but little water flowed, and with the dry grass and twigs projecting from it, thickly coated with crystal ice and glistening frost, we found the plainly-colored, diminutive mud-minnows hidden among the pebbles and sandy ridges of the brook-bed.

Charles C. Abbott, M. D. 
 Trenton, N. J., March 2, 1874.
 
ANIMAL MIGRATIONS.

To the Editor of the Popular Science Monthly:

I believe that grasshoppers (locusts) migrate solely on account of an enemy—a dipterous insect much resembling the housefly, but larger, quicker, and grayish in color, owing to the white hairs at the edges of the articulations. This insect deposits its eggs in the upper part of the locust's abdomen, when the latter is resting on the ground, as it cannot do so when flying. Its favorite moment of attack is just as the locust alights from a flight or a hop. In a few days the larva or maggot is about a quarter of an inch in length. Soon the locust dies, when the larva eats its way out and burrows in the ground for transformation. Sometimes four of these larvæ will be found in one locust. I first noticed this in the summer of 1871. In 1872, when a flight of locusts began to arrive, the fly destroyed nearly all that came during the first two weeks, or until cool nights seemed to stop its multiplication. In 1873 I had an unusually fine opportunity to observe the locusts, as they hatched in incredible numbers upon my farm, and devoured my crops. During the whole summer the fly left the locusts no quiet, but drove them to most desperate straits to avoid the attacks; so that, as soon as the locusts acquired wings, they flew away—that is, what were left of them, for I estimate that not one in fifty escaped death. In places where the irrigating ditches prevented them from crawling forward, they were piled two and three inches deep. The ground during the cool of the day would be dotted with white maggots crawling off to find burrows. The locusts did not leave on account of famine, for there were ample fields of grain and other crops untouched; and they would sometimes abandon a field when only slightly eaten. Besides, I have seen the swarm floating all day in the air when still, and constantly alighting and arising, as hunger impelled from above, or the fly from below. I do not find this fly mentioned in Tenney's work on " Entomology." If comparatively new, there is hope that it will work the destruction of the locusts. I also believe the latter can be readily destroyed by the combined efforts of man, as they hatch in exceedingly small areas.

The prairie-dog (Cynomes ludovicianus) is migratory, although it moves slowly, accomplishing hardly more than half a mile a year. Apparently, their object is to obtain fresh food, for they eat root and branch as they go. The leaders are, invariably, the young, who are constantly driven out by their more mature and powerful brethren. Their vacated holes are occupied by owls and rattle-snakes, but whether these prove enemies or not I do not know.

I strongly suspect that the cause of migration in the lemmings is the parasites which infest their bodies. These, after a few years, increase to such numbers as to be unendurable; then the lemmings set out and are never known to return until they have overcome their enemies in the flood.

S. E. Wilber. 
 Greeley, Colorado, Feb. 28, 1874.
 

 
MR. SPENCER AND THE WOMEN.

Sir: Two papers have already appeared in your columns relating to Mr. Herbert Spencer's "Study of Sociology:"—a direct review of the work, January 10th, to which Viscount Amberley has given the credit of fairly appending to it his own name, thus placing his comments on the author's view of women on the true class-footing of their being the judgment of a man; and a letter, December 20th, confined to this point, to which, through its being signed only with the initial "L.," class-weight of this sort is entirely wanting, notwithstanding the actual force of its remarks—thus forming, as I wish to argue, a notable instance of the undesirableness of that practice of signing by mere initials which is contended for in another article of the first-mentioned number, on the ground of its being a protection to the modest, retiring, sensitive nature of some writers who yet feel that they have something to say which would be well said. My object, then, is now the twofold one, of on the one hand repeating (with some difference) the main arguments of "L.," under the avowed character of a woman; and on the other of pressing upon my fellow-women the present necessity, as especially called forth by Mr. Spencer's recent work, of women not indulging on this occasion in the moral timidity which the hiding of their real names is the effect of. It is the peculiarity of the case that, as all writers have hitherto been taken for granted to be men, there has sprung a natural desire among actual women-writers to play a trick on the public, which has thence caused them as much as possible to force the matter of their own thoughts into the mould of those of men. And although, perhaps, there may be little harm in this where it is fiction alone that is concerned, I contend that it is really a deep injury in relation to those practical questions with which specially all the literature of journals must be occupied.

I share strongly with "L." the disappointment which he or she expresses on the turn which to me also appears indicated in Mr. Spencer's design against the present desire arisen in women to take their part in the social regulating of their country. I mean, chiefly, as to those appended statements of his, cast as if casually into the foot-notes at the end of his volume, which, however, contain in this peculiar instance what must be taken by his readers as a sort of a priori basis to his whole intended reasoning on the subject to come; the whole statements, crowded into almost a single page, regard matters on which it is the very claim of women that no settled opinion is yet possible. Mr. Spencer signifies that whatever fruits of the higher kind of intellect women possibly may produce are, nevertheless, by a certain degree of "normal limitation," to be accounted of as mere mental monstrosities—mere aberrations from the true course of development which is the only profitable course. He obviously thinks it nothing against such course that some of the number of men should exclude themselves from the ordinary duties of domestic and social life, in order that, by strained efforts at intellectual illumination, they may guide those self-efforts of commoner men, which, in the case of men, he asserts are the only true means of real culture; but with women he implies that all such seclusion can inevitably produce nothing of any value so long as men are at hand to afford the required lights. Nothing but an absolute dearth of men present to do that for women which normally they cannot do for themselves—the case referred to being specially that of ascertaining their own social status—can justify the alleged wasting of their real powers! Surely this is a reversal of his plan for men, threatening a philosophic tyranny in his future scheme over the true instincts of women, which the latter cannot possibly feel to be justice to them.

Most needfully, then, in the face of such threatened injury on the part of a writer who is daily becoming more and more of deserved weight in social topics, must women look to one another; that is, for the openly expressed class-feeling which manifestly is the thing that is now called for. The best thing that has been said for us by Mr. Mill, and that for which I think, for one, we owe him a debt of gratitude never to be extinguished, is that, after all, women must speak for themselves. Unless they will do so, this most generous of our advocates has said, it must remain "impossible that any man, or all men taken together, should have knowledge which can qualify them to lay down the law to women as to what is, or is not, their vocation" ("Subjection of Women," p. 48). Let me, however, add, on the other side, that in my own view this demand of self-expression from women by no means includes any equal need of immediate political action. Until the subject has been well thought out between men and women, with much more of careful study than is compatible with popular agitation, I am convinced that any too eager pressing forward toward practical arrangement of it must be dangerously premature. And for this end I believe truly that we need, not only all the instruction that Mr. Spencer can give us, both philosophic and scientific, but all the strenuous mental effort on the part of at least those who must take lead among us, which he seems to condemn. I recognize fully that we can in no way do better than to take him as our teacher—however little he may perhaps himself approve of this—provided always that in learning from him we remain true to ourselves.

 I am etc., Sara S. Hennell. 
 Coventry, January 20, 1874.
Examiner.