or animal structures, such as the cells that cover over the mucous or lining membrane of the intestines, and seem to have the power of growing at the expense of the latter, which they therefore destroy. Hallier soon set to work to cultivate this growth, and in due time produced a microscopic plant which possessed characters that allied it in nature to a fungus, which constitutes the white masses seen in the thrush' of infants, and which belongs to a genus called Oidium. This oidium afterwards bore as fruit other forms of growth, which rank with 'mildews' and moulds. Varying his experiments, Hallier procured, under conditions similar to those which obtain in cholera, a phase in the development of the fungus which exactly resembled a form which grows on diseased cereals, and is called Urocystis. It occurs in true cholera excreta. (It must be noticed here that microscopic fungi assume in the course of their growth, under the influence of different circumstances, a diversity of form, and that what are now known to be varieties were formerly regarded as distinct species.) Well, Hallier infers from his experiments, and especially his inability to produce the urocystis form of fungus except in the contents of the intestines of cholera patients, that this form is not indigenous in Germany, but that it has travelled with cholera from India. He does not, moreover, believe that 'the original habitat of the fungus should be the human intestine, which is under much the same conditions in India as in Europe; but he sees in the high temperature of the intestine a condition capable of maintaining this fungus in activity. A similar high temperature, as provided by the mean climate of India, and by the extreme summer climate of Europe, also furnishes the condition requisite for the development of the fungus outside the body. Thus in summer, and in summer only in European latitudes, could the fungus find in earth and night-soil the necessary temperature for its increase.'

The uro

cystis form, then, that which is supposed to be peculiar to cholera, requires a high temperature for its life, and it is confidently asserted by Hallier that if it be the contagious agent or material of cholera, cholera 'cannot maintain itself permanently in our latitudes,' because of the cold which exists. Hallier then believes that this cholera fungus travels in the intestines of cholera patients from India; and he has pointed out the source from whence it may be possibly derived. Hallier 'recalls the fact that other forms of the fungus under consideration (for variation in form is characteristic of fungi) are peculiar to cereal plants, and that the urocystis with its characteristic cysts, inhabits the delicate and highly nitrogenized tissues of grasses; and he asks whether the cholera cysts may not also, in their native soil, be parasites to some graminaceous plant in India, just as the form (tilletia) which can exist in an European climate is a parasite upon the

imported cereal wheat, which acclimatizes itself in these latitudes.' We now come to the most interesting part of the matter. It seems that the fungus experimented upon by Hallier is identical with that which grows upon the rice-plant when in an unhealthy condition, and it is therefore important to consider whether diseased rice has any influence upon the development of cholera. When the cholera was first studied by English physicians, it was called in India the rice disease' (morbus oryzeus). In the year 1833, Dr. Tytler, in a paper which he had read before the Medical Society of London, stated that he was prepared to submit to the members a statement of facts of the utmost importance, in proof of an opinion which he entertained that the disease which had been described under the name of the Asiatic cholera, and which was said to have arisen in Jessore in 1817, was occasioned or kept up in India by the consumption of unsound rice as an article of food.' Dr. Tytler exhibited various samples of 'ergoted' rice in London, and found rice of a like character selling in the shops. Many travellers and others have at different times called attention to the fact of intestinal ailments having been produced by the use of diseased rice."

ZOOLOGY.

INCARCERATED FROGS.-A near neighbour, upon whose veracity I can rely, recently opened a drain, when he made the following discovery. At the mouth of the drain were placed two large stones, in measurement nearly two feet square, and three inches thick; the one at the top rested closely upon the one beneath. Upon lifting it from the lower stone, the skeletons of five frogs were discovered; they were in a circle in the centre of the stones, quite flat. Upon taking one of them up, and holding it to the light, there was only a threadlike appearance of bones between the dry, flattened, and fleshless skins: these skins were clear, and beautifully marked. In this state they were seen by several persons, and by each of them the frogs were considered to be dead; but when the water commenced to flow over them, there was a slight gasping perceived in the throats of each, by degrees the bodies swelled, and life and motion returned! Then, to the surprise of the beholders, the frogs sprang up, and ran away into the drain. How did these frogs get beneath the stone that covered the lower one so closely? There was no space for them to enter or depart, and upon the surfaces there was not the slightest indention made by the frogs. It was supposed to be thirty years ago since the stones were placed over the drain.-S. G., Benenden, Kent.

FLY ACARUS.-My friend Mr. S. having captured a fly for the purpose of microscopical amusement,

observed two small insects escape from the under surface of its body. We took the measurements of one of these insects, and found that in its greatest length it was exactly inch, and in its greatest breadth inch. The jaws were extremely sharppointed, and moved by lateral action. The two anterior members (A) were armed with grasping claws similar to those of a lobster. The next two (B) terminated in spongy-looking enlargements, from which proceeded numerous hair-like processes of considerable size. The third pair were longer and more distinctly jointed, and terminated in

a tuft of hairs. Next came the six legs, the first pair of which possessed two hooklets at their extremity, whilst the rest terminated in fine points. I enclose a sketch of one of the insects traced by a "Beales' tinted camera," and an enlarged view of the more complex members. On further investigation, Mr. S. and myself have since discovered other parasites of somewhat different character upon the common house-fly, so that such things appear to be less rare than we at first imagined. Whether or not this be the case, we should much like to hear the opinion of more learned correspondents.-4. M.

CAT AND SQUIRRELS. Some two years ago, when living at Kelvedon, in Essex, I found a squirrel's nest, and having taken two young ones, tried to rear them with a bottle. But under this treatment they did not thrive well; so, it being suggested that we should give them to a cat that had recently been deprived of her young ones (I must say with some misgivings as to their reception by "Tabby"), I gave them to her. To my great surprise, she nurtured them as kindly as if

readers of SCIENCE-GOSSIP to know that, after a storm last year, a superb specimen of Banks Oarfish, or Great Ribbon-fish, was cast up on the shore at Seaton Carew, in Durham. It is 15 feet long, and by far the finest example I know; it is stuffed with care, and placed in a large case. It is the property of Matthew Lamb, of Seaton Carew, who will answer any questions respecting this rare production of our seas.-E. Wood, F.G.S., Richmond, Yorkshire.

DEATH'S-HEAD MOTH LARVE.-In July last I took six larvæ of Acherontia atropos, feeding on the tea-tree (Lycium barbarum); all were coloured and marked similarly to those usually described, viz., green with diagonal lilac stripes. Three of the larvæ, during their last change became insects of a totally different colour. The description of these last is as follows: length, 44 inches; general colour, olive-brown, the sides rather darker than the back-in some instances the oblique lateral stripes entirely wanting; the markings on the back form the letter X on each segment; the lower portion of this X is but one-third the size of the upper. The marking on the back, as a whole, present the following appearance

XXXXX

Fig. 205.

They are of an indigo-colour. The body is covered with whitish spots about the twentieth of an inch apart, each having a black point in the centre; the thoracic segments have the ground colour of a pinkish white with an irregular brown-black longitudinal division, and faint white lines dividing the same longitudinally and transversely; the colour from the under side of the body runs in an irregular form into the white segments; the front of the head, which in the usual form is green, is in this variety greyish-white pencilled with lines. Five out of the six larvæ have buried themselves. I have separated the varieties, and shall watch with interest the appearance of the perfect insect. I have not been able to detect any sound from the larvæ.-John Berney, Croydon.

[The most interesting feature in the above account is the fact that the variation took place at a period subsequent to the early stages of the larvae, which were at first all so exactly alike that no trace of variability could be distinguished.-ED.]

BOTANY.

FERTILIZATION BY INSECTS.-The mode of fertilization in the American Laurel (Kalmia) has already been well described, but I fancy I may be excused for adding my testimony concerning this beautiful and interesting plant. When the anthers are liberated from the pockets in the corolla, the stamens suddenly straighten and throw jets of pollen often for a foot or more, "acting," as Professor Gray used to say, "like a boy's peashooter." Many times when the dew was on, I have seen the common honey-bee and other Hymenoptera about these flowers. When the bee alights on a flower, the style comes up between the legs where they join the body, or sometimes further back against the abdomen. In this position they turn around, as though they were balanced on a pivot, generally inserting the tongue outside of the filament, and, while doing this, pull the stamens with their legs towards the centre of the flower, releasing them and frequently receiving the shots of pollen on theirown body. A single visit from an insect is sufficient to release all the anthers. By noon it was a difficult matter to find a flower which had not been visited in this way. Insects seem to be absolutely necessary for the perfect fertilization of Kalmia angustifolia and K. latifolia, for I tied small nets over some flower-clusters (corymbs), and found that when the bees were kept away, the flowers withered and fell off, most of the anthers still remaining in the pockets, and the filaments so decayed that their elasticity was entirely gone. The very few anthers liberated were probably brought out by the shaking of the bushes by the wind. Considerable pollen was found stuck on the corollas by the nectar, which was uncommonly abundant, as no insects of much size were allowed to remove it. The wind might have carried some of this pollen to other flowers, or it might have dripped from those above to flowers below in drops of water (there were two showers during these experiments); but I infer this was not the case in the examples mentioned, because the flowers, especially the stigmas, remained fresh much longer than those which were left exposed to the visits of insects.-W.J. Beal, in American Naturalist.

BLUE PIMPERNEL.-Yellow and Red Pimpernel are common enough, but I never met with the blue variety before this morning. Surely it must be very rare-rare as it is lovely. I came upon it quite by accident, having nearly lost my way in a wood, and doubtful of finding anything like a beaten path, and unwilling to retrace my steps, if indeed that would have been possible; I made my way, at last, through a partial opening in a hedge, and emerged at once into a turnip field. It was here, while gazing with delight upon the expanded wings of a splendid "Admiral butterfly," and soon after

being charmed with the sight of a large fritillary, that I found a large bunch of the lovely blue pimpernel, of which I send one of the two sprigs I plucked. By leaving the rest, I am in hopes the flower will seed, and so produce more; and thus, at some future season, give delight to the botanist, who, like me, may be fortunate in finding it. If any of the readers of SCIENCE-GOSSIP have found or may find, the Blue Pimpernel, it would be very interesting to have the locality recorded.-G., Ilfra combe.

DOUBLE BITTERCRESS. I found lately, near Dublin, a curious double variety of Bittercress (Cardamine pratensis). When first it blossoms, there is nothing peculiar about it, only the pistil is a little larger than usual; but after the petals fall off, the ovary, instead of containing seeds, becomes changed into a bud, which opens out into a very double flower, without stamens or pistil. The flower continues for a considerable time, new petals coming out in the centre as those outside die away. My attention was called to it by seeing upon the same plant both single and double flowers.-C. B. Ball, Dublin.

HAMPSHIRE LYCOPOD.-The following letter, with the editorial remarks appended, appeared in the Gardener's Chronicle for August 3rd :-"I gathered the enclosed specimens of Lycopodium alpinum at Lower Wagner's Wells, in the parish of Bramshot, Hants; the soil a sandy peat, the elevation not more than 600 or 700 feet, the situation sheltered, and growing near to the roots of Heath, about 18 inches high, by which it appears to be almost smothered. Has Lycopodium alpinum ever been properly described? All authors describe it with a repent stem above ground; our plant has one an inch below the surface, but it agrees in every other particular with L. alpinum, its four-garious habit distinguishes it from L. complanatum. May it (L. alpinum) not have sometimes a running stem above ground, and sometimes under? Lastrea Thelypteris, in its native bogs, runs above the soil, but under cultivation it grows with a subterraneous rhizome."John Lloyd.

"There are some doubts as to the true name of this Lycopodium, arising from the fact that the specimens sent are the barren stems only. Professor Babington 'inclines to place it under L. chamaecyparissus, R. Br.-a plant of the Rhine valley.' It may be L. alpinum, but the subterranean rhizome is unlike that species."-Ed. Gard. Chron.

PEAR-TREE IN BLOOM.-There is a pear-tree in Sir Allan Bellingham's garden at Castle Billingham in full bloom, and, at the same time, having pear on it each as large as two walnuts.-T. A. H.

[Similar occurrences were common last year.— ED.]

STICKS WITHOUT END.—The note in last number, signed "H. Pocklington," relating to a "stick without an end," reminds me of some remarkable phenomena of this kind which came lately under my observation. In the demesne of Lord Hill of Hankstone, in Salop, and near the windmill end of the pool, there is a large beech tree in which I counted twenty-three cases of "sticks without end." Mr. P. calls the phenomenon a freak of nature. I regard it as a striking contrivance of Nature to strengthen and maintain the symmetry of the tree fabric. In the case I refer to, this design is most palpable: the general rule appearing thus-a branch from above dips down and grows into one of the immense lower limbs of the structure, thus connecting it with the trunk and affording support more effective than bands of iron could do. -Wm. Hindshaw, Salford.

SONCHUS PALUSTRIS, L. (Marsh Sow-thistle).— Those amongst your readers who are botanists, and they are doubtless many, will probably be interested in knowing that one of the rarest and most magnificent plants which are indigenous to these islands, still flourishes luxuriantly in a habitat seemingly secure from all but the most determined and systematic depredators. It does not appear that this plant has ever occupied a prominent position in the British Flora; our experience justifies us in assuming that, wherever seen, its peculiar appearance and imposing habit has attracted an attention at once fatal to its existence; we know, too, that marsh and fen, the only condition of soil in which this plant can flourish, are, and have long been, gradually disappearing in many parts of the country: it is not surprising then that, marked for destruction whenever observed, and finding the conditions necessary for its being withdrawn from around it, it should have been compelled to seek immunity from violence, as well as a congenial atmosphere, in the most secluded spots that remained for it, at length becoming almost extinct. It was, however, my good fortune a few days since to penetrate an extensive retreat of this rarity, though I believe I have not materially injured its prospects thereby. Being on an excursion in a large tract of barren and desolate country accompanied by two other botanists, we came to a large morass overrun with reeds of the tallest growth, and walking along a high bank adjacent, we noticed some gigantic plants overtopping the reeds at various points whose flowering heads were remarkably conspicuous; availing ourselves of a boat which was luckily at hand, to cross a deep stream intervening between us and the reeds, we were constrained to get out and wade through the tangled mass, which, though standing in nearly two feet of water, entirely forbade ingress to the boat. Forcing our way in through about twenty yards, we came upon a fine cluster of the plants,

and noble ones they were, towering above our heads; the reeds were nearly seven feet high, but the Sonchus was considerably taller, the largest specimen being quite eight feet from the crown of the root to the summit of the inflorescence. There were many other clusters visible at intervals in the swamp; but having succeeded in securing a fair specimen (as well as in getting uncomfortably wet), we retired, thinking ourselves amply repaid for our exertions. Those who have seen the recent plant in the full height of its luxuriant beauty, can say with me that it is indeed "a plant which once seen is never to be forgotten.”—Jas. W. White.

[We much regret that our correspondents who make communications like the above do not permit us to insert their full addresses as well as their names; it would add so much more weight to their testimony.-ED.]

PHYLLACTIDIUM PULCHELLUM.—In the spring of last year, while watching the manœuvres of a water-spider in a jar of Anacharis and Lemna, obtained from the "Heigham osier carr" adjoining the river, almost within the city, I detected adhering to the glass on the side furthest from the light some minute green discs which turn out to be this plant. I put up two slides in glycerine and camphor water-and what is most remarkable, they have continued to grow and fructify. There were no sporcells at first visible, but these have become developed, and are most abundant; some showing the green spores within, while others have discharged their contents, and whole colonies of young ones of from one to two or three cells are now making their appearance.-W. Kencely Bridgman, Norwich.

MICROSCOPY.

AMERICAN DIATOMACEOUS DEPOSITS.-The Monmouth deposit is an example of a class of sediments which are very common in this country, especially in the Eastern States. I have over fifty similar. They are the result of the accumulation of the dead lorica of recent Diatomacea, and generally form at the bottom of ponds; sometimes they accumulate to a considerable depth. I examined one that had been traced down over ten feet. They are not truly fossil, which I take to mean containing for the most part extinct species, but perhaps 'might be called posttertiary, as some one has dubbed them. However, I consider them as but recent deposits of existing forms. I know of no deposit of fresh-water Diatoms of an age as old even as the Tertiary, and I have examined scores of them, and have several now under examination for the State Geological Survey of California.-A. M. Edwards, New York, U.S.

THE STONE MITE.-If any person living in the country wishes for an interesting opaque object for

his microscope, let him search diligently for the ova of the above-named Acarus (Tetranychus lapidum). They are of pearly whiteness, cup-shaped, with a cover slightly larger than the cup itself, and marked with a number of raised lines radiating from near the centre to the circumference. This cover is, I believe, pushed aside, when the larva makes its entrance into the world. The ova are to be found on the upper surface of stones, on open downs, and in similar situations; the masses standing boldly out, so as to be plainly conspicuous to the naked eye. When placed under the microscope, they bear considerable resemblance to some forms of minute fungi. A friend of mine has found them in this neighbourhood (Clifton), on a singular nidus, viz., the paper envelope of used-up cartridges, which had been fired off by Volunteers while practising. The acari have taken advantage of the tiny folds and sinuosities in the paper, and have filled them with irregular rows of ova. The fact of the ova being found on paper shows that the acari do not confine themselves (as their specific name would imply) to stones. A notice of this curious acarus may be found at page 22 of SCIENCE-GOSSIP for 1865, and again at page 126 of the volume for the present year, where there are also figures of the animal and its ova. The central portion of the ovum in this figure is not quite accurate. It should be "umbonate," not plane, much less depressed at the centre.-W. W. Spicer.

SLOUGH OF AMOBIUM.-A friend, a few years since, gave me the exuvia of the larva of some beetle which he had found in an old book in his office, asking me if I could inform him to which of the coleoptera it belonged. This I was unable to do, and until lately had no opportunity of learning anything respecting it. One day, looking into a closet in my study, the receptacle of many odds and ends, I found an old tray, divided into compartments, and which had been made for some round game of cards: this was so perforated by the larva of Amobium that

Fig. 206. Scales from Larva of Amobium.

it broke on laying hands on it. In one of the compartments, in the midst of a quantity of the dust from these borings, lay some of the beetles and three. or four of the larva-sloughs which I instantly re

The

cognised as the same I have alluded to. body is divided into twelve segments, covered with scales of two kinds; one, comparatively broad and marked with fine striæ, the others long, narrow, and hair-like; attached to the last segment is a bunch of very long hairs. The jaws are strong and of a brown colour; antennæ short, and appearing to consist of only three or four joints; the legs terminated with simple claws. The scales and details of the head are well seen with a 4-inch objective. I may observe that the ticking sound, familiarly known as the death-watch, proceeded at all hours during the spring, from the above-mentioned closet, leading me to think that the amobium produced it.—J. B. B.

CENTRING OBJECTS.-Mr. G. Guyon describes his very ingenious manner of centring objects upon slides; but I think I have a better. For a long time I have been in the habit of picking out single specimens of Diatoms and mounting but one on a slide. Thus I can keep my cabinet in order, and in time have representatives of every species. I used for some time a white card having a space three inches by one set out on it, and with a small black spot at the centre. On this I place my slide, and the spot serves as a guide to place the object. Small Diatoms are readily seen against the black background. I have now a card with a raised edge, made of thick cardboard, around three sides of it, and three ink spots, so that I can at once drop the slide into its place, and mount on it one or three objects, each under its own cover. I cannot understand why so many persons find difficulty in making Diatoms stick to the slide; my experience has been that, if they are not quite clean the dirt holds them well enough, and if they are clean, that they often hold so tight when dry that it is even difficult to brush them off.-A. M. Edwards, New York, U.S.

DIATOMS OF BRITISH COLUMBIA.-Mr. J. K. Lord, in the appendix to his "Naturalist in Vancouver Island and British Columbia," enumerates 119 species of diatomaceæ found in gatherings made by him in British Columbia, and on the shores of Vancouver Island.

PARASITE OF HARVEST-MEN (Trombidium phalangii).-Among the thyme I noticed one of those long-legged cousins of the spiders that are familiarly called Harvest-men; it was the common Phalanguim cornutum. I was first induced to look at it by the under parts appearing of a bright red hue, which, however, was derived from the Scarlet Mite (Trombidium phalangii), which so commonly infests the insects of this genus. I counted no fewer than forty-eight of the little pests, all sucking the poor wretch's juices from his belly and legs.-Gosse's "Tenby."