possible to wriggle himself first to decomposition, and then to death.-Monthly Microscopical Journal, July, 1876.

A WRESTLING - MATCH BETWEEN ANTS AND WASPS.

New facts regarding the habits and psychology of insects are of peculiar interest nowadays. Mr. Rothney, of Bengal, describes a wrestling-match between an Ampulex, the destroyer of the cockroach, and some ants. On visiting a tree he was surprised to see an unusual commotion going on between these two species of insects. "All over the trunk of the tree were couples engaged in a series of struggles or wrestling-matches-wasp versus ant; and so many individuals were occupied in this way, and their actions were so rapid, that for some time I could make little out of their proceedings." He therefore watched the movements of a single wasp, which was evidently keeping guard over a piece of smooth bark almost eighteen inches in diameter. An ant would come on the ground and meet the wasp halfway, when, after a series of manœuvres on the part of the wasp to get her favorite hold, she would jerk the ant a clear foot off the tree, and another and another ant would be treated in the same way. “During the time I watched the tree, I saw at least twenty ants thrown, but not one wasp 'tackled.' What was most curious was the fact that all this appeared to go on without the least ill-feeling between the contending parties, and a careful examination of the defeated ants showed them to be none the worse for their falls. I watched several; on their reaching the ground they seemed to be a little bewildered, but, soon recovering themselves, made for the tree again; two, in particular, in the most plucky manner, went straight for the spot from which they had been hurled, and tried another bout with the old opponent." This would seem to corroborate Huber's statement that he saw ants wrestling and playing with one another.-Entomologists' Monthly Magazine, September, 1876.

THE METAMORPHOSES OF BEETLES.

M. Perris, distinguished by his works on the metamorphoses of the insects of the pine, particularly of the beetles and flies, is publishing an elaborate work on the coleopterous larvæ found in the several species of chestnut, beech, and

oak of France, particularly of the department of Landes. These three kinds of trees are closely allied, and so are the insects found upon them, many insects common to one species feeding indiscriminately upon the others; for example, almost all the beetles which live on the chestnut also prey on the oak. An important practical question is answered by Perris, whether the boring grubs of beetles attack healthy or sickly trees. Under the influence of the authority of Ratzeburg, and of facts imperfectly observed and appreciated by him, the forestry schools, and indeed the entomologists, both of Germany and France, had admitted that wood-boring insects attacked only healthy trees. But Perris insists that such insects, which make their attacks in great numbers as if acting by concert, and which consequently are very dangerous, usually only infest sickly and enfeebled trees. "This rule-for it is one-applies without exception, as I know, to insects whose larvæ pass their whole life or a part of it under the bark, namely, to those which are the more numerous and the more dangerous. The circulation of the sap in the inner layers of the bark of healthy trees, naturally very active, become still more excited by the presence of the larvae, and thus they become smothered, as I have seen from examples thus killed." Certain beetles and other insects are an exception to this rule, such as Compsidea, etc., and there are species of this genus in America which destroy elm and other shade-trees while in health.-Annales de la Soc. Linnéenne de Lyon, 1876.

THE EYE OF FLIES.

Signor G. V. Ciaccio has published among the memoirs of the Academy of Sciences of Bologna an account of the anatomy of the eye of Diptera, describing the optic ganglion and optic nerve, the retina of which he finds composed of five coats, though still much more simple than in vertebrates. He then describes the pigment, the external envelope of the eye, and finally the trachea distributed to it.-Journal de Zoologie.

THE SEVENTEEN-YEAR CICADA.

Professor C. V. Riley has shown that there are thirteen as well as seventeen year races of this Cicada, and has pre

dicted that "in the year 1876, and at intervals of seventeen years thereafter, they will in all probability appear from Raleigh, N. C., to near Petersburg, Virginia; in Rowan, Davie, Cabarras, and Iredell counties in North Carolina; in the valley of Virginia, as far as the Blue Ridge on the east, the Potomac River on the north, the Tennessee and North Carolina lines on the south, and for several counties west; in the south part of St. Mary's County, Maryland, dividing the county about midway east and west; in Illinois about Alton; and in Sullivan and Knox counties, Indiana." Specimens since received from Lexington, Virginia, were proof of the correctness of the prediction in regard to Virginia. While this insect requires thirteen or seventeen years, according to the race, for its underground development, the actual development has never been watched from the egg to the mature insect. In 1868 he had collected together in a particular spot near St. Louis a large number of the hatching eggs of a thirteen-year brood which will appear there again in 1881, and he had been able to obtain and note the development of the larvæ every year since. They are now (1876) about two thirds grown.-American Naturalist, October.

HOW COCKROACHES AND EARWIGS FOLD THEIR WINGS.

Several years ago Dr. Saussure, of Geneva, published some interesting observations on the structure of the wings of cockroaches. He treated particularly of the folding of the wings in those forms where the wing is very ample, and some contrivance necessary to insure its complete protection by the small wing-covers. The necessity of some peculiar arrangement in the winged genera of earwigs, where the extended wing is often ten times larger than the wing-covers, is even more evident, and to enable one to understand the subject Mr. S. H. Scudder gives a résumé of Saussure's paper, with additions of his own. In the earwig (Forficula) the wings are folded much as in the cockroach. The mode in which they are opened would be much more difficult to understand if it had not been observed by Charpentier, and described nearly forty years ago. The contraction of the extensor muscles attached to the hinder set of veins would undoubtedly cause the fan to expand when once the double folding, transverse and longitudinal, had been overcome; but

it does not seem possible that they could cope with this dif ficulty. How, then, is it done? According to Charpentier, simply by means of the forceps with which the extremity of the abdomen is always provided in both sexes; the tip of the body is bent upward and the forceps used with great rapidity and ease, first on one side and then on the other, as a sort of fingers, to bring the wings into the position which would allow the action of the thoracic muscles upon the base of the principal veins. Still, adds Mr. Scudder, it is difficult to conceive how this operation can be performed by those species whose forceps are as long as their body.-American Naturalist, September.

THE LIFE OF THE COMMON HOUSE-FLY.

The life of the house-fly has thus been summed up by Dr. A. S. Packard, Jun. It lives one day in the egg state, from five days to a week as a maggot, from five to seven days in the pupa state-in all, from ten to fourteen days in the month of August-before the winged adult period. It is often asked how long-lived a fly is. Most of the flies which are born in August live for a month or six weeks, and die at the coming of frost, either of cold or from the attacks of fungoid plants. A few probably winter over and survive until midsummer, and thus maintain the existence of the species. -American Naturalist, August, 1876.

THE PHENOMENA OF DIGESTION IN THE COCKROACH.

In a late paper on this subject, Professor Felix Plateau concludes that the food after being swallowed accumulates in the crop, where it is acted upon by the salivary fluid, which is usually alkaline. There the starchy substances are transformed into glucose; this first product of digestion is here absorbed, and is not met with in the rest of the digestive canal. The valvular apparatus, which does not play the rôle of a triturating organ, allows small quantities of the matters in process of digestion to pass into the middle intestine of limited capacity. This median intestine, or stomach, as it is usually called, receives the sugar secreted by eight glandular cæca, the sugar being ordinarily alkaline, never acid, neutralizing the acidity as the contents of the crop gradually increase, transforming the albuminoids into bodies soluble and

assimilable analogous to peptones, and emulsionizing the fatty portions. Finally in the terminal part of the intestine are reunited the residues of the work of digestion, and the secretions of the Malpighian tubes, which are purely urinary in their nature. These researches complete and confirm throughout the results of Plateau's former researches on the digestion of insects, published in 1874.-Bulletin Academie Royale, Belgique, XLI., 1876.

A NOISE-PRODUCING SPIDER.

Mr. Mason has exhibited to the Asiatic Society of Bengal specimens of a gigantic spider, of the genus Mygale, which possesses the power of making a strident noise. The sonorous organ of this animal is a comb formed by numerous elastic teeth of a chitinous nature, placed upon the lower face of the maxilla, and a scraper, composed of an irregular range of fine points on the external side of the chelicera. The apparatus is found in both sexes, as is the case with many of the coleoptera, instead of being restricted to the males, as among the orthoptera and homoptera.-14 B, IV., 528.

THE AFRICAN LOCUST IN GERMANY.

During the prevalent fear that the Colorado potato-bug will be introduced into Europe, an equally or even more dangerous pest has actually made its appearance in Germany in the shape of the African locust, Acridium migratorium, which has been found in the fields of Kerzendorf, on the Berlin and Anhalt Railway, where the insects have laid waste extensive tracts of land covered with good crops of grass and grain. Appreciating the necessity of prompt measures, however, the proprietors of the lands put a large force to work, and succeeded in destroying a great part of the insects before they could escape, digging numerous ditches and canals into which they could be swept and then covered with lime. Whether these insects laid their eggs before they were killed is of course impossible to know at present.-17 A, August 1, 1875, 117.

INEQUALITY OF THE SEXES IN A SAW-FLY.

Mr. Smith, at a late meeting of the Entomological Society of London, read some notes on Nematus gallicola, the gall