simple Monera, being drop-like masses of protoplasm, even without a nucleus, and discovered in Smith Sound. It is extremely doubtful whether this is an organism; possibly it may be only a portion of the jelly-like secretion which is produced so abundantly in the deep-water growths of the diatomaceæ.

ZOOLOGY.

Mr. F. Buckland states, in a late number of Land and Water, that the green-bearded oysters found not far from Southend, Essex, owe their green color to the sporules of the sea-weed called "crow-silk," which grows abundantly in the Roach River; and that chemical analysis does not show the slightest trace of copper or other mineral, while the vegetable pigment itself imparts a peculiar taste and agreeable flavor to the meat of these plump little oysters.

At a recent meeting of the Academy of Natural Sciences at Philadelphia, Professor Leidy explained a seeming phosphorescence of the water observed in cloudy afternoons as due to the reflection of light from minute mirror-like appendages of small crustaceans. He also exhibited a tape-worm said to have been taken from the inside of a large cucumber!

In some researches on Filaria hematica, made by MM. Gatch and Pourquier, and published in Comptes Rendus December 27, 1876, they found these worms in the blood of the fetus of a bitch whose heart was filled with them; but they do not explain how they traversed the double walls of the placenta in order to pass from parent to offspring.

The Poduride, or "spring-tails," of Sweden have been monographed in an elaborate way by T. Tullberg. The memoir is accompanied by twelve plates, and enters quite fully into the anatomy of these little creatures of so much interest to microscopists. The work appears in the Transactions of the Royal Swedish Academy.

BOTANY.

Not long since, it was thought that the want of chlorophyl determined the parasitism of plants, as well as serving to distinguish between fungi and algæ. The discovery of a chlorophylaceous fresh-water alga as a bright emerald-green parasite by Professor Cohn, in 1872, was the only known exception. At a late meeting of the Dublin Microscopical

Club, Professor E. P. Wright exhibited and described a second species, marine, found growing and developing itself in the mucilaginous tubes of a Schizonema. It is smaller in size than Cohn's species, but with an emerald lustre scarcely less than that of the fresh-water species. It seems to be thus established that chlorophyl-bearing plants sometimes need, and are capable of assimilating, already formed carbon compounds, hitherto supposed to be only a characteristic of the fungi.

In the Monthly Microscopical Journal for January, 1877, Mr. Worthington G. Smith has an interesting paper called "Notes on Pollen," and illustrated by four plates, which show how extremely pollen grains differ in size, form, and external marking; giving sometimes a valuable clue to a plant's relationships, though sometimes pointing in various contrary directions, since plants have not descended one from another in a straight line, but possess complicated relationships with plants belonging to several different natural orders.

In a paper read before the Royal Society and printed in No. 179 of their Proceedings, Mr. F. Darwin, M.B., maintains that the glandular hairs, or trichomes, found on both surfaces of the leaf of the common teasel (Dipascus sylvestris) contain true living protoplasm, inasmuch as they undergo violent contraction upon application of reagents of widely different natures, but not with osmic acid, which, it is well known, is destructive of protoplasmic structures, and does not cause them to contract. Under normal circumstances the filaments appear animated by the perpetual tremble of Brownian movement. The contraction commences by the filament becoming shorter and thicker at a number of nearly equidistant points, situated close together near the free end of the filament. The beading spreads rapidly down the filament, which ultimately runs violently together into a ball seated on the top of the gland. Since the movements of the filaments are not governed by forces residing within the gland, but are composed of an essentially contracting substance protruded from the leaf-glands, the only theory which seems capable of connecting the observed facts is that, while the glands were originally only resin-secreting organs, the protoplasm that originally came forth as a necessary con

comitant of secreted matters, coming into contact with nitrogenous fluids, gradually adapted itself to retain its vitality and take on an absorptive function.

A valuable contribution to microscopical diagnosis in botany is M. Packenham Edgeworth's compact and convenient book on "Pollen," just issued by Hardwicke, London. It is illustrated by twenty-four plates, from drawings by the author, and these afford abundant evidence of the taxonomic importance of pollen; and the book is not only valuable for reference to adepts, but still more extensively interesting to amateurs. The work is exceedingly meritorious and full of valuable facts, and it is creditable to its author and British botany.

M. Henneguy, in a paper recently read before the French Academy, states that Volvox minor is diœcious, while the V. globator is monœcious. The former is a colony of unicellular algæ, sometimes composed of vegetable cells only, having young colonies in their interiors, sometimes containing male elements (androgonidia), situated in the thickness of the gelatinous wall, and sometimes female colonies, containing only gynogonidia, or oospheres, in the interior.

The androgonidia are formed at the expense of a vegetative cell. The gynogonidia likewise spring from a differentiation of a vegetative cellule. The fecundation is effected through the liberation of antheroids by the dissolution of the antheridial wall. These volvoces, male, female, and neuter, seek the light and keep near the surface of the water; but when the female colonies are fecundated, they get away from the surface.

In a paper read lately (September 26) before the Cryptogamic Society of Scotland, Mr. Worthington Smith, F.L.S., explains very fully the structure of the commɔn mushroom. The entire substance is made up of excessively small bladder-like cells, one and a half billion to every ounce of the mushroom's weight. The spores are produced apparently two at a time at the base of each basidium: there are really four, for at the time of dropping off the first two, the last two appear. These spores will, on germination, reproduce the species, but their life is very short. Once germinated, however, and forming the spawn, or mycelium, this has great tenacity of life, and is commonly, if not always, perennial.

In the April number of the Monthly Microscopical Journal is an interesting paper, by Professor Giovanni Briosi, of Palermo, on the phytoptus of the vine. This disease, producing protuberances, or cecidii, on the leaves, oftentimes numerous and confluent, and, in fact, covering the whole leaf -convex on the upper and concave on the under side of the leaves-is due to punctures and irritation produced in the texture by the acari, which lodge in the cecidium and live on the leaf. The acari were termed phytoptus, to express that they are really and solely parasites of living plants. They are invisible to the naked eye, and the male cannot be distinguished from the female with certainty. They have but four legs, though Landois supposed that there were two other (rudimentary) pairs, and that in their complete development they possessed four pairs of legs, like other acari. Professor Briosi considers that Landois is mistaken, and that these animals constitute a special genus of acari which have only four legs. These arachnida possess a most extraordinary tenacity of life, moving the legs twenty-four hours after immersion in glycerine. In the autumn they emigrate from the leaves to nestle under the bracts which cover the winter buds, and they have been found alive in buds which had been exposed shortly before to a cold of -10° Fahr. In the spring, with the swelling of the buds, the animals regain their activity, and lay eggs, which are deposited directly on the young leaves of the developing bud, and the young ones are scarcely born when they find already within reach the food which nourishes them; and the galls, or cecidii, appear under the form of small spots, scarcely raised, and of a slightly different color from the rest of the leaf, but readily seen by allowing the sunlight to shine through. Repeated careful pruning of the stems which showed the disease the preceding summer, and cutting off the attacked leaves, will, in Professor Briosi's opinion, in a few years result in the destruction of this unwelcome visitor.

In the Monthly Microscopical Journal for November, Dr. Hinds calls attention to the motile protophytes in the leaves of Hypericum androsæmum and H. calycinum. They are to be found in the minute light-colored punctæ near the margin of the leaf, which are translucent from the absence of chlorophyl. They are extremely active, and not of uni

form size, and their nature and function are still left in obscurity.

At a recent meeting of the Linnean Society, Mr. Francis Darwin read an account of some microscopical researches on the glandular bodies on Acacia spærocephala and Cecropia pellata, serving as food for ants, and first mentioned by Mr. Belt in his "Naturalist in Nicaragua." In Acacia were two kinds of glands-(a) nectar-secreting glands at the base of the petiole; (b) small, flattened, pear-shaped bodies, which tip six or seven of the lowermost leaflets of the bipennate leaves. In Cecropia cylindrical bodies are developed in flat cushions at the base of the leaf-stalk. The structures are homologous in kind-cellular protoplasm-and contain oil globules, stores of nutriment which undoubtedly the ants live on.

MICROGEOLOGY AND MINERALOGY..

The anniversary address of H. C. Sorby, President of the Royal Microscopical Society, delivered February 7, is mainly devoted to the application of the microscope to geology. The object-glasses used must be of comparatively small angle, e. g., a one eighth of 75°; large angles are positively detrimental, not only causing the object to be almost, if not quite, invisible, from the absence of any dark outline, but the focal point of such lenses is so near their front surface that it is quite impossible to penetrate sufficiently deep down to see the minute fluid cavities in the centre of grains of sand, or to reach the fine particles lying on the surface of the glass slip below the thickness of balsam necessitated by the presence of large grains of sand.

In a paper read before the Royal Microscopical Society, April 4, 1877, by A. Rénard, on the "Mineralogical Composition and the Microscopical Structure of the Belgian Whetstones," the author states that they owe their excessive hardness to garnet, instead of finely divided quartz, as hitherto supposed; in fact, they contain scarcely any quartz. Thin sections seen by transmitted light show myriads of globular forms so excessively minute that their regular bounding lines and frequently lozenge-shaped faces are not attacked in the polishing process. Sometimes they are gathered together at one point; again, they form lines, or chaplets, or are isolated. These minute rhombo-dodecahedral forms, or globular