means to go through actions which it would not ordinarily perform voluntarily, so that to a bystander it would almost appear to have undergone a course of training. Professor Goltz made some curious investigations on the source of the croaking power of the frog. Of its own accord it never croaks when deprived of its brain; but can easily be induced to do so by stroking it softly down the back from the front to the hinder part with the damp finger, every stroke being accompanied by a croak of satisfaction. From a number of such animals a complete concert of frogs can be obtained in this manner. The mutilated frog possesses also the power of preserving the equilibrium of its body. If placed on a book, to which a gradual inclination is given, it climbs to the upper edge, on which it supports itself by its forelegs, and repeats the process every time that the inclination is changed. Under similar circumstances an unmaimed frog would quickly hop to the ground. The movements of the frog, from which the brain has been removed, differ from those of the unmutilated animal in this respect, that they are performed mechanically, and with the regularity of a machine. It would also appear, from these experiments, that the nerve-centres for the voice and for the power of maintaining equilibrium reside, not in the brain, but in the spinal cord. — Academy. THE COMPRESSED BURBOT OR EEL POUT. In the March (1869) number of the NATURALIST is a paper with the above title by Wm. Wood, M.D. After giving the history, locality, number of specimens and their description, he then says: "The Lota compressa probably visits the salt water, as it is taken in ascending the Connecticut, or its tributaries, in the spring of the year in company with fish from the salt water ascending to spawn."

My first acquaintance with this rare fish was early in the spring of 1859. A specimen was brought me from West River, about a mile north of our village, where that stream joins with the Connecticut, and where it was "hooked up" while angling for other fish. Afterwards in 1864, another specimen was caught in the Connecticut River, opposite our village, with a baited hook set for eels. Both were of such extraordinary dimensions (being severally twelve and fourteen inches in length) that I published the fact, because I knew that the specimen of Lesueur, who first described the species was only six inches in length, and that of Storer who gave a description of a second specimen from Ashuelot River was eight inches long. As I had lived many years near these waters, and supposed myself to be well acquainted with their different denizens, and, moreover, had never seen this genus before, not even their fry, I was led to inquire whence they came.

It first occurred to me that they might have come up from the salt water, but the many impediments in the Connecticut, which are such well-known obstacles in the way of the migrations of fish, forbade at once the entertainment of this idea. Be that as it may, an incident has recently come to my notice which may shed some light on their early history, and certainly on one of their species.

On our farm is a swamp of about three acres, from which issues a rivulet, perhaps three feet wide and three to five inches deep. I have known for some years the existence of a peculiar fish in this little stream, for on approaching its banks I have often perceived quick efforts at concealment. of something in the dark mud of the little pools along its coast. All my attempts to obtain a full view of the fish proved fruitless, but I judged by the ripples it made on the surface of the water, while passing shallow places that it must be some three or four inches in length. Recently whilst our woodchopper was at work in this swan.p, he cut down a tree which fell into one of these pools, and a fish was thus thrown out upon the snow. It proved to be a veritable Lota about three and onequarter inches long. It resembled Lota compressa in every particular, except that its thickness might have been greater in proportion to its length.

This rivulet empties into Whetstone brook, a stream ordinarily about two rods wide and two or three feet deep, and has a bed differing little from that of the Connecticut River. I have lived by this stream a number of years, and have never seen a Lota in its waters. The Whetstone empties into the Connecticut about a mile from the mouth of the rivulet. In this distance are two obstructions, partly natural and partly artificial, one thirty feet, the other twenty feet high, so that it cannot be supposed that there is any egress from the river to the rivulet by water.

The fishes of the Whetstone are Salmo fontinalis Mitch., Rhinichthys atronasus Agas., Boleosoma Olmstedii Agas., Semotilus argenteus Putn., Plargyrus Americanus Putn., and Holomyzon nigricans Agas.; the three latter were introduced by me some twenty years ago. I have been thus minute in giving all possible data, in order that a better judgment may be formed, whether these swamps are the breeding places of Lota compressa, or whether the specimen mentioned above may not be a new species.

The train of thought to which a solution of these questions might give rise, would naturally lead us to examine into the effects that purely local or particular causes may have upon the development and forms of fish life. With respect to the size of this specimen, being much smaller than those found in the Connecticut, we may say, that all fish of the same species found in large streams are generally larger than those found in small ones. We have a perfectly analogous example at hand in regard to the Salmo fontinalis of the Connecticut, which occurs of larger dimensions than in the Whetstone, the disparity being as striking in the latter case as in the former. - CHARLES C. FROST, Brattleborough, Vt.

A WHITE WOODCHUCK.—It may interest you and some of your readers to know that I have obtained a perfectly white woodchuck, a perfect albino of Arctomys monax of Gmelin. There is not a dark hair on his body or tail, and his eyes are of a clear, rich, carnelian color. He was caught on North-west hill in Williamstown, Mass., and brought to me alive. From the first he fed freely on clover, especially the clover heads,

and made a nice nest for himself from the part discarded as food; in this nest he spent most of his time taking nearly the form of a ball. He always exhibited a readiness to bite, and it was not safe to touch him with the hand. One day I carried him, in his small cage, to my lecture room, and afterwards put him in my private room and left him alone. When I returned I found him out of the box or cage, and bottles and trays of natural history specimens scattered upon the floor. After disturbing things generally he had taken up his position behind a large box of fossils. From his retreat he looked as unconcerned as if nothing had happened. Without much trouble I secured him in his box again, and carried him home and put him in a large cage in my cellar which is well lighted and ventilated. About midway between the top and bottom of this cage is a shelf which touches the bars or slats in front, and extends backwards about half the depth of the cage. This shelf was put in so that the woodchuck might have something to rest upon besides the floor of the cage. After the cage was done it was desired to turn it so that what is naturally the back should be the bottom, the slats or bars thus being on the top instead of at the side; this brought the shelf into a vertical instead of a horizontal position. Now observe what this woodchuck did: he gnawed through the edge of this shelf, which was against the bars, in order to get into the other part of his cage, although there was a space of eight or ten inches below the lower edge of the vertical shelf for the whole width of the cage, and when he was disturbed he often run through this hole instead of going along on the bottom.

I was interested to see that he used everything he could get to enlarge and perfect his nest, not only all of his discarded clover stalks, and the rags which I gave him, but also all the chips which he gnawed from his cage. But he did not get thoroughly tamed, and so availing himself of the absence of a board, which had covered a hole which he had been gnawing, he squeezed out through the hole, scaled the cellar wall, and escaped through an open cellar window. A few weeks afterwards he was killed by a farmer's dog, and I have sent his skin to Mr. Jillson to be mounted.

Mr. Hitchcock of this town, informs me that he has seen a living white woodchuck in New Lebano, N. Y.-S. TENNEY, Williams College.

RARE BIRDS IN NOVA SCOTIA. I observe in the last number of the NATURALIST a note on the occurrence of the Pomarine Jager (Lestris pomarinus), on the Susquehanna River, Pennsylvania, in July last. On the 4th of October, my friend, Mr. William Gilpin, shot a fine specimen at Digby, on the Bay of Fundy shore of this Province, which is now in my possession. I see in the " Report of the Birds of Massachusetts," that Dr. Brewer also obtained it some years ago in Massachusetts Bay.

Another rare visitor to a latitude so far north, was taken in our harbor about the time of the severe revolving southerly gale of the 30th of January last, the Purple Gallinule (Gallinula martinica, Baird). This is the first instance on record of its capture in Nova Scotia. J. MATTHEW JONES, Halifax, N. S.

GEOLOGY.

GIGANTIC FOSSIL SERPENT FROM NEW JERSEY.- Professor Marsh describes in "American Journal of Arts and Sciences," under the name of Dinophis grandis, a new and gigantic snake from the Tertiary formation of New Jersey. He says "the earliest remains of Ophidia, both in Europe and this country, have been found in the Eocene, and nearly all the species from strata older than the Post Pliocene appear to be more or less related to the constricting serpents. Remains of this character are not uncommon in European rocks, but in this country two species only, one founded on a single vertebra, have been described hitherto, and both of these were discovered in the Tertiary greensand of New Jersey." The vertebra described "would indicate an animal not less than thirty feet in length; probably a sea-serpent allied to the Boas of the present era."

In closing, the author states that "the occurrence of closely related species of large serpents in the same geological formation in Europe and America. just after the total disappearance in each country of Mosasaurus and its allies, which show such marked ophidian affinities, is a fact of peculiar interest, in view of the not improbable origin of the former type; and the intermediate forms which recent discoveries have led paleontologists, familiar with these groups, to confidently anticipate, will doubtless, at no distant day, reward explorations in the proper geological horizon."

MICROSCOPE OBJECTIVES.

MICROSCOPY.

- A performance of a 4-10 objective made for me by Mr. William Wales, of this city, is of such a superior character that I have no doubt it will be of interest to many of your readers. With direct or central light in contradistinction to oblique, and with the diatom mounted not dry, but in balsam, the Pleurosigma angulata is beautifully resolved; the three sets of lines being brought into view with great distinctness, and this with the No. 1 or A eye-piece. Amplification 210 diameters. With no equal power of Powell & Leland's of London, of Hartnack of Paris, of Tolles & Grunow of this country, or of Gundlach of Vienna, various objectives of each and all of which makers I have examined, have either, I myself, or other microscopists of my acquaintance been able to effect this. Another feat which I had recently the honor of exhibiting to several members of the "Bailey Microscopical Club" of this city was a resolution of the podura scale with its light central markings with this same 4-10. The resolution of the striæ on human muscular fibre by a 3-inch objective, also made by Mr. William Wales of this city, again challenges our admiration. -J. J. HIGGINS, M. D., 23 Beekman Place, New York.

[We referred this note to Mr. E. Bicknell, who kindly sends the following reply. - EDS.]

Messrs. Editors of the American Naturalist:-In answer to your question in regard to the above communication, I would say that while fully concurring with Dr. Higgins in his high estimation of Mr. Wales' objectives, I am of the opinion that he (Dr. Higgins) has either made an error in his measurement of amplification (210 diameters with the No. 1 or A eyepiece) or that the 4-10th objective is very much underrated in magnifying power. All of Mr. Wales' 4-10th objectives which I have seen have been as near or nearer 1-4ths than 4-10ths in magnifying power; and below I give a table of amplification of such 4-10th objectives as are at hand; also two 1-4ths for comparison:

The measurements were made with a first-class stand and eye-pieces of Zentmayer, the image of a stage micrometer being thrown down by a Spencer's camera lucida, and measured at just ten inches from the eye; cover adjustment for 125th cover glass. It seems to me that there should be some uniform standard adopted by the different makers of objectives, so that the 1-4th of one maker may not be as high as the 1-6th of another maker; or a 4-10th of one be as high as a 1-4th of another; or, still worse, a 3-inch objective of one maker of precisely the same power as a 2-inch of another maker, which was just the case with two objectives which I had about one year since. If the objectives did not differ any more than the first three in the above table it would be an improvement. The amplification which Dr. Higgins gives to his 4-10ths is as high as the highest 1-4th in the above table. - EDWIN BICKNELL, Salem.

ANTHROPOLOGY.

THE BONE CAVES OF GIBRALTER. - The four Genista Caves, Martin's Cave, St. Michael's Cave and some others, have yielded evidences of early man, in the form of osseous remains, associated with flint knives and flakes, stone axes, polished and chipped; worked bones, serving as skewers, arrowheads, needles and gouges; anklets or armlets of shell, hand-made pottery, querns, rubbing-stones and charcoal. With these were found remains of numerous animals,* including Rhinoceros etruscus, Rh. leptorhinus § (extinct); Equus, Sus priscus (extinct); Sus scrofa, Cervus ela

Those marked thus §, are abundant; and thus §§, very abundant. A single molar of Elephas antiquus was obtained many years since by the late Mr. James Smith, of Jordan Hill, in an old sea-beach (now demolished) at Europa Point, the southern extremity of the rock.