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CORRESPONDENCE.

Disease" explains so many phenomena which I have noticed, that I am disposed to accept it with avidity. Nevertheless, there seem to be some contradicting facts. Once, when serving with a troop of cavalry, a young and apparently healthy beef was brought to us, which we slaughtered, and set about cooking immediately. To our surprise, the flesh was tainted. To the senses of taste and smell the taint could not be distinguished from incipient putrescence. A careful examination failed to detect any signs of disease in the entrails or any part of the animal. The time which elapsed from the killing of the beef until the flesh was tasted was only a few minutes, certainly not half an hour. It was in Louisiana, in the month of April, late in the evening, and in cool weather; notwithstanding unprejudiced stomachs and resolute appetites, we were obliged to desist, and make a hungry camp.

Another instance, and much more incompatible with the bacterial theory of putrefaction as set forth by Prof. Tyndall, I find in Dr. Kane's narrative of his Arctic expedition. I have not the work at hand to refer to the page, but it is where, in the early dawn of the arctic morning, he watched several times for a reindeer which had been indistinctly seen, in the faint light, haunting a valley about a mile or two from the ice-bound ship. He finally succeeded in killing it, and his men ate one meal; but the carcass putrefied before they could eat again. This, and the temperature of the air many degrees below zero! He goes on to say that the sudden putrefaction of meat in the arctics is common; that sometimes a bear or a deer would spoil before it could be flayed. Can it be that there are arctic bacteria?—that in warmer countries there are exceptional kinds which hasten putrefaction at such a rate? Can it be that the cells of the flesh in certain circumstances produce putrefaction, somewhat as the cells of fruit produce fermentation? Or, finally, is it so that, both in the case of Dr. Kane's reindeer and in that of my beef, the animal had eaten something which gave the flesh a bad flavor, and our imagination supplied much more than we supposed? The facts need some explanation, and, in the case of Dr. Kane, are of such weight as should challenge the general attention of observers.

M. M. Kenney.
Beenham, Texas, March 25, 1877.

THE ORIGIN OF HONEY-DEW.

Dear Sir: Mr. Darwin says, in his last work, "Cross and Self Fertilization in the Vegetable Kingdom," page 402: "Many years ago I suggested that, primarily, the saccharine matter in nectar was excreted as a waste product of chemical changes in the sap; and that, when the excretion happened to occur within the envelopes of a flower, it was utilized for the important object of cross-fertilization, being subsequently much increased in quantity and stored in various ways. This view is rendered probable by the leaves of some trees excreting, under certain climatic conditions, without the aid of special glands, a saccharine fluid, often called honey-dew." In the mountains of North Carolina there is a species of honeydew eagerly sought for by bees, which is rarely seen by persons who have written of it, and is by many supposed to be a myth; but Mr. Rufus Morgan, one of the best informed and most successful apiarians of that section, who has for several years examined it in all its stages, is convinced that it is an animal, not a vegetable exudation. In reply to my questions respecting it, he writes:

"The phenomenon is not only well known in my section of the State, but is of annual recurrence. I have frequently studied it on green leaves, generally in the month of June or July, and invariably found it in close vicinity to the well-known aphides, or plant-lice, always below them, whence I concluded they wounded the leaves and caused this sap or 'honey' to flow. But, on further examination, I was fortunate enough to witness an actual shower of dew, in almost infinitesimal globules; and, on getting the sunlight at the right angle, these particles could be traced to these little creatures.

"It was a perfectly quiet day, and they seemed to eject the globules with some force, making them fly clear of the leaf and fall on the leaves below. Of course, such small particles would be wafted away by even a gentle wind, and, not being accompanied by their cause, their origin would necessarily be obscure.

"Last spring, before any leaves were out, I witnessed a most extraordinary yield of it on the pines. It hung in great drops, and fell off like real dew when the branches were shaken. At first I was mystified as to its origin, as I could find no aphides, which, according to my theory, ought to be present; but on a closer inspection I found them in abundance, not on the green, but on the dark or woody part of the twig. As these little insects are of the same color as the substance on which they are found, they are noticed only by close observers; but there is no doubt in my mind that the honeydew is an exudation from them. These insects are also called 'ant-cows,' from the fact of ants seeming to suck them, when they are only gathering this sweet secretion. It will be hard to convince the public of this simple origin of the honey-dew, as, of the hundreds with whom I conversed respecting it last year, none would accept my views,