Ordinary Form Research Articles

Societies and Academies

Societies and Academies

A VEST POCKET OPHTHALMOSCOPE CASE.Read in the Section of Ophthalmology at the Forty-first Annual Meeting of the American Medical Association, held at Nashville, Tenn., May, 1890.

I present to the Section an ophthalmoscope case made for me by Meyrowitz Bros, in 1886, and which I have had in constant use ever since. It is made like a spectacle case, the open end being closed with a tightly fitting lid, or like a flattened pencil case such as is used by school-children. It is made of stiff pasteboard, or other light material, covered with morocco. It presents the following advantages over the form in ordinary use: 1. Size. This is such that it can be carried in the vest pocket. The thickness is about half that of the wooden case. 2. Weight. Being smaller and made of lighter material, it is not as heavy as the ordinary form. 3. Shape. There are no corners and the edges are rounded off. 4. As a result of the shape we have another advantage: It is dust-proof. The lenses are

Societies and Academies.

LONDON.Entomological Society, July 3.—Lord Walsingham, F. R. S., President, in the chair.—A letter was read from Mr. E. J. Atkinson, Chairman of the Trustees of the Indian Museum, Calcutta, in which assistance was asked from British entomologists in working out various orders of Indian insects.—The following motion, which had previously been unanimously passed at the meeting of the Council, was read to the Society:—“That papers containing descriptions of isolated species widely remote in classification or distribution are, as a rule, undesirable for publication, as tending create unnecessary difficulties for faunistic or monographic workers.” Mr. McLachlan, Mr. Jacoby, Mr. Elwes, Dr. Sharp, and others took part in the discussion that followed.—Mr. McLachlan, on behalf of Prof. Klapálek, of Prague, who was present as a visitor, exhibited preparations representing the life-history of Agriofypus armatus, Walk., showing the curious appendages of the case. Prof. Klapálek, in answer to questions, described the transformations in detail. A discussion followed, in which Mr. McLachlan and Lord Walsingham took part.—Mr. H. J. Elwes exhibited a specimen of an undescribed Chrysophanus, taken in the Shan States, Upper Burmah, by Dr. Manders, which was very remarkable on account of the low elevation and latitude at which it was found; its only very near ally appeared to be Polyommatus Li, Oberthur, from Western Szechuen, but there was no species of the genus known in the Eastern Himalayas or anywhere in the Eastern tropics.—Mr. G. T. Porritt exhibited a remarkable series of Arctia mendica, L., bred from a small batch of eggs found on the same ground at Grimescar, Huddersfield, as the batch from which the series he had previously exhibited before the Society was bred. This year he had bred forty-five specimens, none of which were of the ordinary form of the species: as in the former case, the eggs were found perfectly wild, and the result this year was even more surprising than before.—Mr. R. W. Lloyd exhibited specimens of Harpalns cupreus, Steph., and Cathormiocerus sodus, Boh., recently taken at Sandown, Isle of Wight.—Mr. O. E. Janson exhibited a fine male example of Theodosia howitti, Castelnau, a genus of Cetoniidæ resembling some of the Dynastidæ in the remarkable armature of the head and thorax. The specimen had recently been received from North-West Borneo. —Mr. W. White exhibited specimens of Heterogynis paradoxa, Ramb., and stated that this insect represented an extreme case of degeneration, the mature female being only slightly more developed than the larva, the prolegs being quite atrophied. Lord Walsingham made some remarks on the subject.—Mr. T. R. Billups exhibited a fine series of the very rare British beetle, Medon (Lithocharis) piceus, Kr., taken from a heap of weeds and vegetable refuse in the neighbourhood of Lewisham on May 19.—Mr. W. F. Kirby read a paper entitled “Descriptions of new species of Scoliides in the collection of the British Museum, with occasional reference to species already known.”—Mr. J. B. Bridgman communicated a paper entitled “Further additions to the Rev. T. A. Marshall's Catalogue of British Ichneumonidæ.”—Mr. J. S. Baly communicated a paper entitled “On new species of Diabrolica from South America.”

Societies and Academies

LONDON. Entomological Society, October 5.—Dr. Sharp, President, In the chair.—Mr. Jacoby exhibited a specimen of Aphthonoides baccarii, Jac., a species of Haltica having a long spine attached to the posterior femora; also a specimen of Rhagiosoma madagascariensis.—Mr. Stevens exhibited a very dark specimen of Crambus perlellus from the Hebrides, which its captor supposed to be a new species. Mr. Porritt remarked that this brown form of Crambus perle'lus occurred at Hartlepool with the ordinary typical form of the species, and was there regarded as only a variety of it.—Mr. Slater exhibited a specimen of Gonepteryx cleopatra, which was stated to have been taken in the North of Scotland. Mr. Jenner Weir remarked that although the genus Rhamnus—to which the food-plant of the species belonged—was not a native of Scotland, some species had been introduced, and were cultivated in gardens.—Mr. South exhibited about 150 specimens of Boarmia repandata, bred from larvæ collected on bilberry in the neighbourhood of Lynmouth, North Devon, including strongly marked examples of the typical form, extreme forms of the var. conversaria, Hüb., a form intermediate between the type and the variety last named, and examples of the var.destrigaria, Haw. Mr. South said that an examination of the entire series would show that the extreme forms were connected with the type by intermediate forms and their aberrations.—Mr. Poulton exhibited young larvae of Apatura iris, from the New Forest; also eight young larvæ of Sphinx convolvuli reared from ova laid on the 29th of August last. He said the life-history of the species was of extreme interest, throwing much light upon that of Sphinx ligustri, as well as upon difficult points in the ontogeny of the species of tthe allied genera Acherontia and Smerinthus. Mr. Stainton said he was not aware that the larvae of Sphinx convolvuli had ever before been seen in this country in their early stages. Mr. McLachlan remarked that females of this species captured on former occasions, when the insect had been unusually abundant, had been found upon dissection to have the ovaries aborted.—Mr. R. W. Lloyd exhibited specimens of Elater pomonæ, and of Mesosa nubila, recently taken in the New Forest.—Mr. Porritt exhibited a series of melanic varieties of Diurnea fagella, from Huddersfield, and stated that the typical pale form of the species had almost disappeared from that neighbourhood.—Mr. Goss exhibited, for Mr. J. Brown, a number of puparia of Cecidomyia destructor (Hessian Fly), received by the latter from various places in Cambridgeshire, Norfolk, Suffolk, and Wiltshire. He also exhibited a living larva of Cephus pygmæus, Lat. (the Corn Sawfly), which had been sent to Mr. Brown from Swaffham Prior, Cambridgeshire, where, as well as in Burwell Fen, the species was stated to have been doing considerable damage to wheat crops. Mr. Verrall, in reply to a question by Mr. Enock, said he believed that the Hessian Fly was not a recent introduction in Great Britain, but had been here probably for hundreds of years. He admitted that he was unable to refer to any but recent records of its capture. Prof. Riley said he was unable to agree with Mr. Verrall, and believed that the Hessian Fly had been recently introduced into this country. Its presence here had not been recorded by Sir Joseph Banks, by Curtis, by Prof. Westwood, by the late Mr. Kirby, or by any other entomologist in this country who had given especial attention to economic entomology. It seemed highly improbable, if this insect had been here so many years, that its presence should have so long remained undetected both by entomologists and agriculturists. Prof. Riley said it had been stated that the insect was introduced into America by the Hessian troops in 1777, but this was impossible, as its existence at that date was unknown in Hesse. Mr. McLachlan, Capt. Elwes, Mr. Verrall, Mr. Jacoby, and Dr. Sharp continued the discussion.—Mr. J. Edwards communicated the second and concluding part of his “Synopsis of British Homoptera-Cicadina.” —Prof. Westwood contributed “Notes on the life-history of various species of the Neuropterous genus Ascalaphus.”—Capt. Elwes read a paper “On the Butterflies of the Pyrenees,” and exhibited a large number of species which he had recently collected there. Mr. McLachlan said he spent some weeks in the Pyrenees in 1886, and was able to confirm Capt. Elwes' statements as to the abundance of butterflies in that part of the world. The discussion was continued by Mr. Distant, Mr. White, Dr. Sharp, and others.

The Harveian Oration

The Harveian Oration

Improved Arrangement of Scale for Reflecting Instruments

THE inconvenience resulting from the position of the scale in the ordinary well-known form of Thomson's reflecting galvanometer must have been experienced by all who have had occasion to use it much, and especially by myoptic individuals. This I have been able to eliminate very easily, as hereafter described, so that there is no further craning over to see “the spot,” or getting in one's “light” in so doing.

AN IMPROVED METHOD OF OPERATING THE SPRENGEL AIR-PUMP

Professor Rood's paper gave an account of his experiments with the pump for the purpose of obtaining the highest possible vacua. He first experimented with an arrangement similar to the ordinary form of the Sprengel pump, and reduced the pressure to one three-millionth. The exhaustion went on very rapidly at first and then very slowly-slower than the increased rarefaction seemed to call for. This indicated a leakage, and it was found that this leakage amounted in one minute to oneeighty-seven rnillionth of an atmosphere. The form of the pump was modified to correct the leakage, and a vacuum was obtained with a pressure of one-sixtyii.iilionth. It was impossible to get beyond that point, and it occurred to Professor Rood that the potash he used might have given out moisture. He therefore substituted sodium, and the pressure rose only to one-fourmillionth. Anhydrous phosphoric acid was substituted for the sodium, and the pressure fell to one-millionth. It finally struck the experimenter that the trouble was in the gauge, and when a correction was applied to the gauge, vacua were obtained with pressures of one ninety tour-millionth and one hundred and ten millionth. Higher vacua even can be obtained. It had recently been stated in Natlure, said Professor Rood, that his airangeinent was exhibited four years ago at the Kensington Garden, and he would not, therefore, call it new. But the best result obtained in England was one-twenty-millionth, and the best result reached by an eminent French chemist was one-seventeen-millionth. He, theretore, thought there must be at least something new in his method of using the Sprengel air-pump.

The Telephone

AFTER reading the experiments of Prof. Forbes on the telephone, in NATURE, vol. xvii. p. 343, it occurred to me, as probably it has done to others, that this instrument might be employed in comparing the electrical resistances of wires. Accordingly, two weak cells were connected with the ordinary form of Wheatstone's bridge, and the telephone placed in the position usually occupied by the galvanometer. The current was rendered intermittent by a small electromagnetic apparatus belonging to an electric bell; the bell itself having been detached, the intermitter was placed in a separate room, and connected by long wires with the battery and bridge. The German silver wire of the bridge, having a resistance of 2 ohms, was further lengthened at each end by resistance coils of ten ohms, and it was found that with a little practice one could easily compare two resistances of about two ohms within at least 1,000th of the true ratio.

DESCRIPTION OF A NEW DREPANODES

Notwithstanding the variability of D. varus Grote, of which species D. sesquilinea is stated by Dr. Packard to be the ordinary male form, there can be no doubt that a very interesting species from Maine (prof. Fernald)and Massachusetts (Mr. Roland Thaxter) is distinct from any previously described. In this form the exterior line is without a costal angulation. It may be called Drepanodes Fernaldi n.s. ♀ Larger than the other species, light purplish brown. The two transverse lines composed of broken black lunules shaded with white. A black discal point on primaries. A median diffuse brown shade near the exterior line and continued on hind wings. The exterior line extends straight to costa near apices and is here not angulated; it is continued on hind wings, but merely as a white sub-lunulated line with black pointlets on the veins. Terminal space on fore wings shaded with brown. Fringes on both wings pale. Edge of secondaries brown. Beneath paler than above, sub-irrorate. A common white exterior lunulated line marked by black pointlets on the veins. Discal dots on both wings.

3. Experiments with the Telephone

In the telephones used in these experiments the permanent magnets were of the ordinary horse-shoe form, about 4 inches long. No cores of soft iron were attached to the poles, the insulated wire, No. 26, being wound directly round both, in such a way that a current circulating through it followed the direction of Ampère's currents. The vibrating disc was the bottom of a shallow can of thin tinned iron, 2½ inches in diameter, supported directly above the poles of the magnet, and almost touching them.

XVII. Preliminary note on the use of the piezometer in deep-sea sounding

In order to determine the depth of the sea independently of the length of sounding-line used, piezometers filled with distilled water were frequently attached to the line along with the deep-sea thermometers. The combined effects of change of temperature and change of pressure were registered by a steel index of ordinary form. The temperature of the bottom-water being given by the deep-sea thermometer, the effect of temperature on the apparent volume of water in the piezometer could easily be calculated; and from the residual effect, the pressure, and therefore the height, of the column of water to which the instrument had been subjected could be deduced. The piezometer did not differ materially from the ordinary ones used for the determination of the compressibility of liquids. A minute description of the fittings necessary for their safe use on the sounding-line cannot be given without reference to a drawing or model, and must therefore be postponed.

Acherontia Atropos

CAN any of your readers throw any light on the raison d'être of the dimorphism of the larva of the Death's-head Moth {Acherontia atropos)? Some years ago I found five larvæ of this insect on a bush of jasmine. They were all probably offspring of one female. Two of them were, of the dark chocolate-coloured variety so strikingly dissimilar to the normal or commoner type, The imago of one oi the dark-coloured larvæ differed in no respect that I could perceive from the ordinary form. It has occurred to me that the dark variety may be due to its simulating the dead, withered, blighted, or diseased shoots of the potato, as its commoner brother does the healthy leaves and stalks.

Laboratory Notes by Professor Tait a. Photographic Records of the Sparks from a Holtz Machine

To determine the cause of the ordinary zig-zag form of electric sparks, the author requested Mr Matheson, one of his laboratory students well skilled in photographic processes, to take instantaneous photographs of the sparks of the Holtz Machine, by means of a quartz lens, in hot and cold air alternately. Several of these photographs were exhibited, and showed much greater smoothness of the track of the spark in heated than in cold air. The zig-zag appearance seems to depend upon the presence of combustible organic particles in ordinary air, but the experiments are still in process.

On the Germ Theory of Putrefaction and Other Fermentative Changes*

II.THE author next proceeded to describe and illustrate, by diagrams enlarged from camera lucida sketches, some of the variations he had observed in organisms found in the milk glasses when introduced into other media. Another unnamed species of Oidium closely allied to that before referred to, and like it operating as a putrefactive ferment upon urine, was seen to present strange varieties according to the fluid in which it grew and the length of time it remained in it; yet, when placed in boiled milk, it returned to exactly the same character which it had when in the flask of unboiled milk in which it was first observed. But still more remarkable modifications were seen among the Bacteria. One species of very large size, but of ordinary form and movements, as seen first in the milk, presented the following, among other varieties. In Pasteur's solution it grew as motionless algoid threads with nucleated segments. In urine and turnip infusion it did not grow at all, nor did it in the albuminous fluid till boiled and cooled solution of sugar of milk had been added, when it returned to its original Bacteric form at first, but afterwards assumed the characters of a toruloid organism. In boiled milk it resumed the original Bacteric character, but, after seven weeks, the Bacteria had changed from very large to excessively minute ones.

IV.—Notes on the Genus Rostellaria (or Aporrhais?) of the Gault

Having read Mr. Price's note and description of Rostellaria maxima in last month's Number (p. 97, Pl. VI.), I venture to express my regret that so doubtful a species should be published with the apparent authority of the GeologicalMagazine to confirm it; especially as Mr. Wiltshire (than whom there is no one better acquainted with English Cretaceous Mollusca) is of opinion that it is only a giant form of Rostellaria carinata. The description given by Mr. Price would equally apply to the ordinary form of R. carinata which occurs in the same bed, and, save in size, exactly resembles it. The most distinctive portion of the shell, the wing, is unfortunately not preserved. The examples of Rostellaria carinata found in this bed, I may remark, always differ slightly in form, being broader and more obtuse (they are also usually more crushed and imperfect) than those from the lower beds. I am fully; convinced that, if size alone is sufficient ground to justify the formation of new species, we shall speedily find the present confusion of names in the Gault fauna more hopelessly involved and more impossible to unravel than ever. What, for instance, would be the result of the adoption of such a basis of nomenclature for the Cephalopoda from the same formation ?

The Spectrum of the Aurora

THE following observations on the Spectrum of the Aurora were made by Mr. Alvan Clark, jun., in the neighbourhood of Boston, on the evening of October 24. He used a chemical spectroscope of the ordinary form, with one prism, and photographed scale illuminated with a lamp. Four lines were seen at the points marked 61, 68, 80, and 98. To reduce these to wavelengths, the next day I measured the lines C, D, E, b, F, and G with the same instrument, and deduced the annexed table:—

IX. A new ozone-box and test-slips

The ordinary form of Ozone-box being very cumbersome, the present one has been contrived to supersede it. The box is simple in construction, small in size, and cylindrical in form; the chamber in which the test-slips are hung is perfectly dark, and at the same time there is a constant current of air circulating through it, no matter from what quarter of the compass the wind is blowing. The air either passes in at the lower portion of the box and travels round a circular chamber twice, until it reaches the centre (where the test slips are hung) and then out again at the upper portion of the box in the same circular manner, or in at the top and out again at the bottom of the box. Fig. 1 represents a section of the upper portion of the box, showing the manner in which the air enters and moves along to the centre chamber (where the test-slip is hung at A), and figure 2 represents a section of the lower half of the box where the air circulates in the opposite direction, leaving the box on the side opposite to that on which it had entered.

On Apparatus for Dredging at Moderate Depths in the Deep Sea, and for Capturing Floating Objects from Shipboard

ABSTRACT During a recent voyage from India, the success attending the use of certain appliances contrived by me for capturing such marine objects as came in our way, induces me to offer the subjoined account of them to the public. I may mention that, although familiar with the ordinary form of towing net and sounding apparatus, it struck me that much more might be done by resorting to some simple form of casting net, than is possible where the chapter of accidents is relied on for bringing within the jaws of the towing net the objects required, and by constructing some more portable sounding apparatus, which would at the same time prove effective at moderate depths, and bring up a much larger quantity of material than is attainable under the ordinary sounding lead, or the more complicated and cumbrous contrivance of Lieutenant Maury and others. I would further premise that whoever desires to make a collection of marine floating molluscs, tunicaries, ascidians, and the like, and also the minuter organisms which exist in all latitudes in the open ocean, to a greater or lesser extent, will be grievously disappointed if he imagines that the trailing net used astern of a ship will suffice for the purpose. For, to be at all successful, constant and unremitting watchfulness is, in the first place, essential ; and what is equally important, a fitting place of observation at the stern of the vessel, with ten or twelve feet of the water bend. In my own case, the quarter gallery of a 1500-ton merchantman afforded the best of all look-out ports ; and from it I was enabled to use the casting net about to be described with ease and certainty. In the clear blue water of the open sea it is astonishing how rapidly the eye accustoms itself to detect creatures of the minutest size ; and how readily it learns to distinguish, even in the small patches of calm water between each wave when a considerable sea is running, any object that may chance to be swimming near the surface. Nor is this confined to the portion of sea immediately below the observer, but it can be done at a distance of several yards. In order to embrace this distance the following casting net was constructed, and in the course of a short practice it became easy to pitch this net, quoit fashion, over any object within such range.

VIII. On the k -partitions of a polygon and polyace

The problem relating to the polyace is the reciprocal of that relating to the polygon, and is not separately discussed. By the k -partitions of a polygon, the author means the number ®f ways in which the polygon can be divided by ( k -1) diagonals, no one of which crosses another; two ways being different only when no cyclical permutation or reversion of the numbers at the angles of the polygon can make them alike: it is assumed that the polygon is of the ordinary convex form, so that all the diagonals lie within its area.

XXII. On the fructification of the submersed algæ

The light which the prevailing spirit of inquiry and observation has thrown on the means of reproduction allowed by nature to vegetable beings, is not yet equally diffused over all of them. Those whose simpler organization seems, when examined, to want some of the parts which we are accustomed to consider as essential to generation, continue to the present mo­ment more or less involved in darkness ; and their fecundation, and means of reproduction, are still objects of doubt and inquiry. Amongst them the Fuci, Ceramiums, Ulvae, Confervæs, all sub­mersed algae, are perhaps in the number of the less illustrated. It is probable that their peculiar way of living, which requires from nature a particular modification in the parts destined to repro­duce them, as well as in the means of performing this opera­tion, has been the principal cause of the perplexity of naturalists on this subject. They have either sought for things in their ordinary form, which nature furnishes to these plants under a different one, adapted to their circumstances; or they have thought that she deviates from her usual ways, when she only makes use of her stubborn versatility, enforcing the execution of her general plan, by the means which at first sight seem to make her deviate from it. In the present memoir I shall endeavour to ascertain what parts of these plants perform the sexual functions : and, in order to be clear, I will first relate in a few words, what has been observed and believed on this point, and proceed afterwards to the exposition of the opinions which observation and the strictest analogy induce me to hold on this subject. Reaumur was the first naturalist who bestowed a proper attention upon the fructification of the Fuci. Two elaborate memoirs of this great man are to be found, in the Parisian Transactions for the years 1711 and 1712, in which he endea­vours to persuade us, that the vesiculae filled with small grains are the female part of the fructification, in the fuci, and the filamentous hairs, which are found in different parts of the frons, the male organs. Pie examined eleven species of fuci, in eight of which he found grains, and only in six the fi­lamentous hairs. It is unlucky for his opinion, that these hairs have no antheras, and still more unlucky, that their existence has no relation at all to that of the vesicles which bear the grains, for they are persistent through all the life of the plant, without any remarkable alteration. Their situation besides is very unfit for the fecundation of the grains, except in the Fucus elongatus. Notwithstanding the weight of these objections, which he did not conceal, this otherwise sensible naturalist tried to the last to support by hypotheses, what he could not fairly prove by observations. His great name, joined to the general ascendency which the sexual system gained a little after all over Europe, gave nevertheless a common currency to his opinion; and it was received, though in a wavering manner, by Linnæus himelf, and, what is more surprising, by the last of the Jussieus. These great men indeed gave it as the prevailing opinion of the day, not confirmed by any sanction of theirs. This was not the case of less profound botanists ; for they, as the fashion then was, attempted to see stamina and antherag, like the common ones, wherever they had not been observed before. I deem it unnecessary to stop a moment to consider the multitude of supposed stamina, which Donati, Griselini, and others, imagined they had found in Fuci, and Ulvæ, be­ cause it is at present clearly evinced that these fancied sta­mina are only organs of nutrition.