withdrawing the pipe, a part of the contents will follow, and by repeating the process several times you can empty the shell. Then fill the blowpipe with water and force it into the shell several times, shake it well, and then blow out the water; repeat it until it is perfectly clean. Be very particular, especially with white eggs, or dark spots will appear after a time, which make the egg worthless. It was while I was blowing a box of about one hundred eggs of Wilson's Tern (Sterna Wilsoni) that Mr. Ellsworth suggested to me a new invention for blowing them. The result is, I can now prepare one hundred eggs in less time than I formerly could ten, and much better, doing all the work with my hands that heretofore has been a severe tax upon my lungs. I will not now describe the instrument, but will say, in brief, that it is invaluable to the oölogist. I would not part with mine for ten times the cost ($3.10) if I could not replace it. This is the testimony of all who have used them. If any collector wishes to obtain this valuable instrument, the inventor, Mr. E. W. Ellsworth, of East Windsor Hill, Connecticut, will supply them. -WM. WOOD, East Windsor Hill, Conn.

THE VISION OF FISHES AND AMPHIBIOUS REPTILES.-M. F. Plateau has advanced the theory "that these animals can see distinctly in the air, and that their distance of distinct vision must be nearly the same in this medium and in water. Although fishes, with the exception of some privileged species, such as the Eel, the Chironectes, and the Climbing Perch, have hardly any need for combining the faculty of seeing distinctly in water with that of seeing distinctly in the air, this double faculty is evidently indispensable to the Amphibia.”—Annals and Magazine of Natural History.

FLIGHT OF BIRDS. - Will you inform us how sailing birds remain suspended in the air? Last summer while standing with Prof. Mudge, on the high bluff of the Kaw, opposite Manhattan, Kansas, a large bird, supposed to be Cathartes aura, rose from the opposite margin of the river, and accomplished a spiral flight of over five minutes duration, supposed to be more than five hundred feet in height, and a mile in linear extent, against a wind blowing about "three" on the Smithsonian scale, without flapping his wings but once, and that was apparently to preserve his bal

ance.

The following suggestions have been made: 1. Birds in sailing do not rise above the initial point, but use their wings as parachutes, like the flying squirrel. The turkey buzzard, mentioned above, rose about three times as high as the bluff. 2. Extended sailing like this is due to the momentum gained by previous flight. The turkey buzzard in this case rose from a perch at the river's brink. 3. Short quills under the wings are used, while the wings proper are stationary! 4. Birds sail against the wind like ships. The resultant force of the sail and keel may be resolved into two forces, one lying in the line of direction of the ship's path. How with birds? Do not sailing birds accomplish the spiral flight when the air is comparatively still? 5. The air raised to a temperature

of 103° Fahr. by the heat of the bird, fills the quills, hollow bones and cavities of the body, and buoys it up. Shoot a hawk or buzzard while sailing, and down he tumbles from his airy perch. Does his body cool as soon as that?

Not one of these suggestions seems to be sufficient. Do they when combined? Will you please enlighten us?-JOHN D. PARKER, Topeka, Kansas.

DEEP-SEA DREDGING NORTH OF SCOTLAND-Drs. W. B. Carpenter and Wyville Thompson report to the Royal Society that the recent dredging expedition to the Faroe banks has "obtained evidence of the existence, not of a degraded or starved out residuum of animal life, but of a rich and varied fauna, including elevated as well as humble types, at a depth of 530 fathoms." "Their researches have conclusively established the existence of a temperature as low as 32° over a considerable area of sea bottom, where the depth was 500 fathoms and upwards, notwithstanding that the surface-temperature varied little from 52°." They argue that there is a stratum of sea water with a temperature of 32°, or even 28°, and the existence of such strata even in equatorial regions, has been regarded by high scientific authorities as proving the existence of deep currents, bringing cold water from polar regions to replace the warmer water that is continually flowing as (notably) in the Gulf Stream, from the equatorial towards the polar regions, as well as to make good the immense loss which is constantly taking place by evaporation from the surface of tropical seas." "The examination which Prof. Huxley has been good enough to make of the peculiarly viscid mud brought up in our last dredging at the depth of 650 fathoms, has afforded him a remarkable confirmation of the conclusion he announced at the recent meeting of the British Association, that the Coccoliths and Coccospheres are embedded in a living expanse of protoplasmic substance, to which they bear the same relation as the spicules of sponges or of Radiolaria do to the soft parts of those animals. Thus it would seem that the whole mass of this mud is penetrated by a living organism of a type even lower, because less definite, than that of sponges and Rhizopods; and to this organism Prof. Huxley has given the name of Bathybius. This calcareous mud, composed partly of these bodies and partly of living Globigerinæ, has been compared to the great chalk formation, and the reporters thus compare the animals found living in it with the marine fauna of the Cretaceous period:

"Among Mollusca we have two Terebratulidæ, of which one at least (Terebratulina caputserpentis) may be certainly identified with a Cretaceous species, whilst the second (Waldheimia cranium) may be fairly regarded as representing, if not lineally descended from, another of the types of that family so abundant in the Chalk. Among Echinoderms we have the little Rhizocrinus. that carries us back to the Apiocrinite tribe, which flourished in the Oolitic period, and which was until lately supposed to have had its last representative in the Bourgelticrinus of the Chalk. Among zoophytes, the Oculina we met with in a living state seems generically allied to a Cretaceous type (0. explanata of Michelin), and the remarkable abundance of sponges, which not improbably derive their nutriment from the protoplasmic substance that enters largely into the composition of the calcareous mud wherein they are embedded, is a pre-eminently conspicuous feature of resemblance. It can scarcely be doubted that a more sys

tematic examination of the remarkable formation at present in progress would place in a still stronger light the relationship of its fauna to that of the Cretaceous period; since the specimens which our few dredgefuls contained can only be considered as a mere sample of the varied forms of animal life which this part of the ocean bottom sustains, -its Urschleim' being both physically and physiologically the foundation of the whole.”

The authors also refer to deep sea forms found in the Mediterranean: "That bivalve and gasteropod molluscs, as well as zoophytes, can exist at depths even exceeding that just named, has been clearly proved by the remarkable observation of M. Alphonse Milne-Edwards (which does not seem to receive the attention it merits), that when the submarine telegraph cable between Sardinia and Algiers was taken up some years since for repairs, several living polyparies and molluscs were attached to portions of it which had been submerged to a depth of from 1093 to 1577 fathoms. Of these, some had been previously considered very rare, or had been altogether unknown, whilst others were only known in a fossil state, as belonging to the fauna of the later tertiaries of the Mediterranean basin."— Scientific Opinion.

HONEY BEES KILLED BY POLLEN.-In an article in the NATURALIST for February on "Honey-bees killed by Silk-weed Pollen," you say "we have never before heard of an insect actually losing its life from this cause." In 1860 my attention was called to the same fact; many hives had their stocks seriously reduced from this cause. On a single specimen I counted over one hundred pollen masses attached to the claws and legs. When the claws are thus fettered, the bee cannot climb upon the combs nor collect honey, and is soon expelled from the hive and must die. The unfettered bees tumble them out with little ceremony. As the common silkweed (milk-weed we call it here) needs insect aid to free its pollen masses, and thus secure the fertilization of the stigma, there are peculiarities in the structure of the flower to secure this result; and for this purpose the pollen masses are attached to a cleft gland. When the insect visits the flower to secure its honey, of which there is an abundance, it must step or the gland to reach the nectary, and a hair or claw entering the cleft becomes fast. To free itself the insect must pull out the gland with the pollen attached or remain and die; and the latter is really the fate of many small flies and moths.-J. KIRKPATRICK, Cleveland, Ohio.

LINGULA FOUND LIVING IN CALIFORNIA. - Mr. Tryon announced that Dr. W. Newcomb had dredged at Monterey, California, one living specimen of Lingula albida Sowb., which is probably the northern limit of the species, and not in accordance with the general rule of distribution. — Proceedings of the Conchological Section of the Philadelphia Academy of Natural Sciences.

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GEOLOGY.

PREHISTORIC PICTURES OF THE CAVE HORSE IN FRANCE.-Prof. Owen states that outlines of the head of different individuals of the cave horse when alive, neatly cut on the smooth surface of a rib of the same species, have been discovered by the Vicomte de Lastic St. Jal, in 1863, in his cavern at Bruniquel, under circumstances which indisputably showed the work to have been done by one of the tribe of men inhabiting the cavern, and slaying the wild horses of that locality and period for food.-Scientific Opinion.

MICROSCOPY.

AMOEBOID MOVEMENTS IN EGGS.-Prof. E. Van Beneden, in some very important researches on the development of the eggs of the lower crustacea, states that there is no vitelline membrane in the egg as it lies in the ovary. He proves it, first, by the amoeboid movements already known of other eggs, and which he has observed to be particularly active in these instances; secondly, by the very interesting fact, of his own discovery, that the eggs at this stage, like the Infusoria, swallow, so to speak, globules of carmine. The same fact has been recorded with regard to the white blood corpuscles and other young cells."-Schwann, in Scientific Opinion.

THE MOLECULAR ORIGIN OF INFUSORIA. — The doctrine of Heterogeny, or spontaneous generation, seems to be slowly gaining adherents. Prof. R. Owen has declared in favor of it, and Dr. J. H. Bennett, the eminent pathologist of Edinburgh, advocates it in the "Popular Science Review" for January, under the title given above. He states that animals and plants are developed from ova or seeds, or by parthenogenesis, or by heterogenesis, i. e., from molecules which compose the scum or pellicle seen on the surface of an infusion of any vegetable or animal substance. These molecules "constitute the primordial mucous layer of Burdach, and the proligerous pellicle of Pouchet. These molecules enlarge, and may be seen here and there strongly adhering together in twos and fours, so as to form a little chain." They continue to unite until they form a short staff, or filament-bacterium. These bacteria become longer by uniting with others, and have a serpentine movement whereby they are propelled forward in the fluid, forming a vibrio. These bodies disintegrate, and thus a second molecular mass is produced. "In this, rounded masses may be seen to form, which strongly refract light not unlike pus corpuscles, or the colorless corpuscles of the blood. These soon begin to move with a jerking motion, dependent upon a vibratile cilium attached to one of their extremities-Monas lens. In a day or two other cilia are produced, the corpuscle enlarges, is nucleated, and swims through the fluid evenly. Varied forms may now occur in the molecular mass, dependent on the temperature, season of the year, exposure to sunlight, and nature of the infusion, all having independent movements. They have been denominated Amabæ, Paramecia, Vorticellæ, Kolpoda, Keronæ, Glaucoma, Trachelius," etc., etc. "At other times it happens that the molecular mass, instead of being transformed into animalcules, gives origin to minute fungi," such as Torula, Penicillium, etc. "In all these cases no kind of animalcule, or fungus, is ever seen to originate from preëxisting cells or larger bodies, but always from molecules."

"That the infusoria originate and are developed in the molecular pellicle which floats on the surface of putrefying or fermenting liquids, has been admitted by all who have carefully watched that pellicle with the

microscope, more especially by Kutzing, Pineau, Nicolet, Pouchet, Jolly and Musset, Schaffhausen and Mantegazza." He holds that the germs of these organisms do not exist in the air, nor multiply by self division, nor are they capable of elongating or aggregating, thus forming filaments or larger masses, unless by the union of other molecules like themselves. Having shown, from the observations of Pasteur and others, that the germs cannot preëxist in the air, he holds that they cannot preëxist in the water, as the numerous experiments by Pouchet, Meunier, etc., have shown that all animal and vegetable germs are killed by boiling them; yet nothing is more certain than that long ebullition of various infusions has wholly failed to prevent the formation in them of animal and vegetable growths," the molecules appearing in them after the water cools. He ascribes their origin to phenomena of a chemical nature, the results of the discussions in the French Academy of Sciences for the last eight years, showing "that not the slightest proof is given by the chemists, with M. Pasteur at their head, that fermentation and putrefaction are necessarily dependent on living germs existing in the atmosphere. They rather tend to show that these are phenomena of a chemical nature, as was ably maintained by Liebig. In conclusion, the author holds that the infusoria, animal and vegetable, "originate in oleo-albuminous molecules, which are formed in organic fluids, and which, floating to the surface, form the pellicle or proligerous matter. There, under the influence of varied conditions, such as temperature, light, chemical exchanges, density, pressure, and composition of atmospheric air, and of the fluid, etc., the molecules by their coalescence, produce the lower forms of vegetable and animal life."

CHICAGO MICROSCOPIC CLUB. - We have received the Constitution and By-laws of this new society, and the Proceedings of the meeting held January 26th, when Prof. Freer exhibited human blood cells showing the cell as a bi-concave disc, with a nucleus appearing as a prominence in the centre; most microscopists having denied the existence of a nucleus in the human blood disc.

ANSWERS TO CORRESPONDENTS.

A. J. O., Morristown. - We would be much obliged for specimens of sheep ticks and their eggs and young, with notes on their habits.

J. S., Lancaster, Pa. - Your notes and sketches of bird parasites were of great interest to us. We would be greatly indebted to ornithologists for specimens of bird ticks, lice, mites and other external parasites, with their eggs and young, as well as parasitic worms, such as the tape-worms and the "round worms." They may be collected in vials of whiskey or weak alcohol, and sent by mail in a strong pasteboard box, or roll of tin. Has any one ever found the bed-bug in swallow's nests; they occur thus in Europe.

S. W. C., Otisco, N. Y.-After making your insect case as nearly air-tight as possible, place camphor in a paper with pin holes, or smear the box with creosote, or keep benzine in constant evaporation in the box. Beetles may be soaked in a solution of corrosive sublimate previous to arranging them in the insect-case. Above all, watch carefully for dust made by devouring insects, which falls to the bottom of the case containing them, by which we may detect their presence in the case.

THE DATE PALM.-In answer to a correspondent who enquires whether dates ever grew so low that a man can pick and eat them as he walks under the tree, we answer