reach of an inch : but about 300 or of an inch may be considered as average-sized specimens.

Fig. 219. Side view of Trinema, showing oblique mouth, contracting vesicle, pseudopodia extended. From a well among Algæ.

Fig. 220. Another lateral view somewhat tilted. From a well, &c.

Fig. 221. Front view, showing rounded subterminal mouth.

Fig. 222. Front view of a more robust specimen from Sphagnum, showing delicate punctations.

Fig. 223. Side view of empty test, showing the inversion of the mouth.

This article is the concluding one as regards the Rhizopods of the order Protoplasta, sub-orders Lobosa and Filosa. In my next I propose to describe two or three forms belonging to the order Heliozoa, which differ in many material points from those previously described.

Rawtenstall.

J. E. LORD.

NOTES ON AN INSECTIVOROUS PLANT.

LL the plants of the genus Utricularia are

A rendered interesting on account of their

peculiarly-constructed bladders. The greater bladderwort ( Utricularia vulgaris), one of the commonest, but not the less interesting of the genus is frequently met with in this country, inhabiting ponds, stagnant

pools, and foul ditches. It floats near the surface of the water, and is entirely destitute of roots. The leaves are finely dissected into capillary segments, and furnished with small bladders usually measuring about one-fifth of an inch in diameter. The lower, or under side of the bladder is nearly straight, and the outline of the upper part rounded and terminating on the outside with several antenna-like prolongations. Thus the whole bladder in appearance bears a striking resemblance to the ". water-flea." The bladder is formed of two layers or cells; the outer layer consists of large polygonal cells containing water, protoplasm, and chlorophyll, and between these much smaller cells are formed also containing protoplasm. The cells of the inner layer are round, and are also accompanied with smaller cells which support four short pyramidal processes terminating in two large rounded cells--sometimes inclined to be elliptical in outline. The transparent and elastic valve or lid, composed of two minute layers of cells continuous with two layers of larger cells, extends nearly to the opposite side of the bladder, and is then folded under, and rests, or rather presses against the collar or peristome. The surface of the valve is furnished with glands, and on the inner side of the collar numerous small bifid processes are crowded together. Both the valve and the collar proceed into the cavity of the bladder, the entire surface of which is studded with quadrifid processes. Animals gain ingress to the bladder by pressing against the free edge of the valve, which being highly elastic shuts again immediately, and thus prevents their escape. From the peculiar structure of the bladders it may be inferred that they are specially adapted for the capture of minute animals. They have been supposed by some naturalists to be air-bladders by means of which the plant is effectually floated in the water, but having cut off all the bladders from several branches, I found the branches to float as well without them as those with them. I have also found several branches destitute of bladders, and they floated well, the only marked difference being that the plant was decidedly weaker than those possessing them. The amount of organic matter held in solution within the cavities of the bladders is considerable for they are nearly always found to contain a greater or less number of minute animals, which ultimately become asphyxiated; disintegration then follows, and absorption begins, for the minute processes-which may be considered analogous to root-hairs-when microscopically examined show their contents to consist of irregularly-shaped masses of matter containing protoplasm. I placed several plants in bell-jars; some were kept in comparatively pure water-the water being changed at frequent periods-while others were kept in water literally teeming with infusoria; the plants kept in the latter condition were not only of a darker colour, but of a more vigorous growth, and the quadrifid processes

of the bladders when microscopally examined were found to be filled with dense masses of matter

containing protoplasm. Plants kept in a purer condition were sickly and much paler in colour, the quadrifid processes being decidedly less dense in their contents.

J. H. A. HICKS, F.R.H.S.

THE DORSAL PORES OF EARTHWORMS. By the REV. HILDERIC FRIEND, F.L.S., Author of "Flowers and Flower-Lore," etc.

IF

F a specimen of the common earthworm is examined, especially after having been preserved for a time in spirits, it will be found that a number of pores exist on the back. They are most readily seen on the girdle as a rule, and look exactly like the holes which result from the puncture of a pin or needle. These openings have been known for a considerable time as the dorsal pores, a name which serves not only to define their position, but also to differentiate them from the other openings which exist on various portions of the worm's body-such as the male or spermiducal pores, the nephridiopores, and the puberty pores (tubercula pubertatis).

It is now many years since these apertures were first detected. Who first observed them, it is impossible to say. Equally difficult would it be to decide who was the first to notice their presence in describing the animals. In 1727 Dr. Derham, Canon of Windsor, wrote a very interesting work, entitled Physico-Theology, in which he endeavours to demonstrate "the being and attributes of God from His works of Creation." He says that under the skin of worms there lies a slimy juice, that they emit as occasion is, at certain perforations between the annuli, to lubricate the body, and facilitate their passage into the earth.' A little later, however, he shows that a certain Dr. Willis had previously written an account of these "Foramina on the top of the back, adjoining to each ring, supplying the place of lungs." Now Willis published his work, De Anima Brutorum, in 1672, so that for upwards of two hundred years the pores have been known to science, to go no further back. It is only in recent years, however, that they have been carefully noted, and the position of the first pore recorded for the different species of worm. It has been thought by some that the first dorsal pore was so uniformly placed in the various species of earthworms that a specific character might be based thereon. This, I am disposed to think, is not borne out by facts.

Dr. Benham, one of our few English authorities on the subject, says: "In many earthworms the coelom is put into communication with the exterior by means of a series of dorsal pores, placed on the intersegmental grooves. In Lumbricus these pores occur in every somite after about segment viii. In Digaster and

Perionyx they commence just behind somite iv., in Plutellus behind somite vi. In Pleurochæta and Typhæus the pores are present only behind the clitellum. They are present in Acanthodrilus, and in many Perichætæ." In Allurus they begin behind segment iii. or iv.

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As will be inferred from the foregoing, a variety of ideas have prevailed respecting the use to which these apertures were devoted in worm economy. Willis says they supply the place of lungs, and if Derham's remarks apply to the dorsal pores, he regards them simply as the openings through which lubricants were poured. Lloyd Morgan is as cautious on the subject as he is inaccurate. He says: 'Every segment of the body, except the first, has a dorsal pore opening into the anterior part of the ring in the mid-dorsal line, and two very minute pores, one on each side of the ventral line, which are the external orifices of the nephridia or segmental organs, whose function is excretory." The dorsal pores are not found in the typical earthworm on every segment save the first, and if they are, we are not favoured by the professor with a vestige of an idea as to their use. He says: "There are no specially differentiated respiratory organs, respiration being apparently effected by the surface of the body," so that he does not regard the dorsal pores as lungs.

The most important contribution to the subject is undoubtedly that which was made a few years ago by Hermann Uhde, in a paper which deals chiefly with the structure of the body-wall in earthworms.* He points out that "the dorsal pore lies on the anterior edge of the segment in which it occurs, and appears on the intersegmental groove. It is absent from the foremost segments, but the position of the first pore is constant for a given species. In the common earthworm it occurs between viii. and ix., and in the turgid worm between x. and xi." Claparade formerly described the epidermis as being folded inwards at the dorsal pore, just as it is where the setæ are situated, but Uhde shows that such is not the case. By stripping off the epidermis I have been able to detect the infolding of the cuticle around the setæ, but not around the dorsal pore, which, as Uhde affirms, is a perforation through the epidermis and the muscular layers. The pore appears, according to Vejdovsky and others, to be wanting in fresh-water worms or Limicola. In some worms, when the girdle is fully developed, the pores become closed through the growing up of the cuticle around the edge. This is not always the case, however, for the mucous worm has been noted by some to be an exception, while I have found that the dorsal pore on the clitellum or girdle of some species is quite as discernible after the organ has attained full develop. ment as before.

"Zeit. f. Wiss. Zool.," xlvi. pp. 85-142. Benham, "Q. J. Mic. Soc.," Aug. 1886, No. cv., pp. 102-4.

If a worm is opened laterally, and the internal organs removed, so as to leave only the body-wall, it will be possible so to display this portion of the animal as to see the whole series of pores in regular succession. It will be easy then to observe that they are connected with each other by a kind of tube which runs right along the back of the worm. I am a little doubtful whether this is what Uhde refers to when he says that the epithelium of the body-cavity passes across the muscular layers and meets the cuticle around the edge of the pore. The pore has a special set of muscle-bundles which form its sphincter muscle.

Uhde does not think there is the slightest connection between the pores and the nephridia, which are excretory in their function. Yet, in a sense, the dorsal pores play their part in the excretory process, since the fluid contained in the cœlom, or body-cavity, as well as certain other substances which in some species of earthworm are coloured, can be caused to exude through them. Sometimes the exudation is in drops, but some foreign species are able to squirt it to a distance of a foot, much as Peripatus does. In these cases the process is perhaps protective.

It is to Professor Busk that we are indebted, through Professor Lankester, for one of the best accounts of these apertures in English. In a remarkable paper on the earthworm, published by the latter in 1865, we have an illustration of the integument of a worm with all the various pores found on the dorsal surface carefully represented. "One of these orifices, situated in the median dorsal line of the segment, appears always to be larger than the others, and penetrates directly to the perivisceral cavity. That these openings form a very ready and frequent means of escape to the colourless fluid may be ascertained by handling a large earthworm, when some considerable quantity is nearly invariably found to escape from its dorsal surface." Nor is this all. Professor Busk says that the fluid expressed from these pores was of a dirty greyish colour, thin and opaque. Examined under the microscope it contained numerous spherical particles and pyriform granular bodies, besides irregular organic particles.

This coloured fluid differs with the species of worm examined. In some, as the brandling and turgid worm it is yellow; in others, as the mucous worm, it is white; while the red worm yields two kinds of colouring matter.

Notwithstanding the large amount of attention which has been paid to earthworms during the past century, we are even now very badly informed on many points connected with their economy, and there is great need that someone with the necessary leisure, means, and scientific training should investigate some of the details more fully. I have been able to make great progress with my work on the distribution and revision of the British Lumbricide-till recently

almost totally neglected-and hope by the due publication of the new and interesting results to stimulate further research on the part of others.

Meanwhile, so far as the dorsal pores are concerned, they appear to be for the emission rather than the introduction of fluids, and are apparently lubricative, excretory and protective. Their homology with certain organs found in other Annelids does not seem to have been carefully ascertained-at any rate I know of nothing on the subject in English.

H

ANIMALS AND MEDICINE.
By HULWIDGEON.
UNGULATA.

WORSE.-Among the more peculiar, not to say nasty, subjects of Bate's "Dispensatory," was an article which, as a soil fertilizer, has probably contributed more than any other such to enrich our larders with vegetable, and thereby animal, produce. And, after undergoing the apothecary's fair imitation of nature's disintegrating process, if it really possessed any curative powers, there was little reason why it should not have been as inoffensively serviceable as a drug. Our forefathers evidently accredited it with a profusion of medicinal qualities, and doing so, perhaps were wise to pocket their squeamishness.

Still, few patients nowadays, I imagine, would choose to swallow the two to six ounces, four times a day, prescribed of Bate's Aqua animalis (p. 2), a cure for "pleurisies, pains, rheumatisms," and other disorders. Yet such was the allotted dose of that compound of some herbal products, distilled treacle, and horse-dung. Salmon did his best to perpetuate the remedy, such as it was, by recommending it in addition against stone, gravel, and urinary affections. Of this kind too was Bate's Potio pleuritica (p. 556), which comprehended two ounces of "juice expressed from horse-dung by mixing with it white wine," and which was "to be taken three or four times a day after blood-letting." But how anybody could stand blood-letting three or four times a day, for any number of days, I am happily not called upon to explain. Concerning this potion Dr. Salmon advises

also gave the dose, one dram twice daily, in a medium, for convulsions and bowel distempers.

The mare was in no less requisition; her milk was administered in a diversity of forms. Caracosmos, Cosmos, Koumiss (with variations of spelling), are some of the names given in medicine to the sour curdle, borrowed from the Tartars, which was not first introduced at the Health Exhibition of 1884, but a common medical prescription a dozen or more decades before that date. Mare's milk in its large proportion of lactose, its abundance of serum, and the softness of its almost inseparable butter and cheese (Hooper, pp. 498 et seq.), possessed distinctive characters which sometimes rendered it more desirable than other milks. The near approach of its qualities, in general, to those of human milk naturally made it an effectual substitute for the latter, and it was sometimes provided in default of asses' milk.

The horse was one of the animals from which bezoar stones were most commonly procured (vide Howard, vol. i. p. 332). Thus, even in death his utility failed us not. Indeed, his carcase rendered us posthumous service worthy of the rhapsodies of the venerable meditator on a broomstick. Its hide when flayed, tanned, dressed, made into shoe-leather, worn out and even decayed, still possessed a benevolent property, for we read (in Howard, vol. ii. p. 970), that "the powder of a burnt old shoe sprinkled on the place," is an effectual healer of galled flesh. Truly, of all the friends of man, this one was faithful to the last!

Perhaps I ought not to omit mention of the ignis sapientium (or "heat of horse-dung "), a favourite means of distilling and digesting drugs which was put into frequent practice by the chemists of old. This was accomplished by placing the matter in a closed vessel, inserting it in a manure heap of the requisite proportions, and dubbed in the vulgar tongue a 'dung-bath" or "horse's belly," and leaving it for a varying length of time, according to the exigencies of the operation. Salmon, who devotes a great deal of instruction to the practical apothecary, sometimes suggests alternative processes, "for want of the conveniency of horse-dung," but usually first counsels its use. For instances of its application it will suffice to refer the reader to pp. 36, 65, 111, 229, and 572 of Bate.

Horsehair was often of essential service to the physician, as, by insertion, to keep open those artificial ulcers yclept setons (vide Hooper, p. 742). Its osseous system too, no doubt, was answerable for a good many of the "calves-foot jellies," and kindred preparations devoted to the strengthening of the weak.

Ass. When the Prior de Jonval indited his celebrated panegyric on the value of the ass, he omitted mention of, perhaps, one of its greatest titles to commendation. As if to counterbalance this shortcoming, another familiar classic, Dr. Buchan, is

exuberant in his encomiums on this single head; pinning his canny faith on the nutritious qualities of the milk this creature affords. "Convulsive or nervous asthma," he tells us (p. 370), "is often relieved by the use of asses' milk; " but his chief recommendation lies in the unstinted praise which he bestowed on it as a sovereign remedy for phthisis, praise which at once elevated it to the front rank of consumption cures, and lent it a reputation which it has not yet lost.

...

In writing of the treatment of consumption, the doctor tells us (p. 163): "Asses' milk is commonly reckoned preferable to any other, but it cannot always be obtained. It is hardly to be expected that a gill or two of asses's milk, drank in the space of twenty-four hours, should be able to produce any considerable change in the humours. This medicine however valuable, very seldom performs a cure. The reason is obvious; it is commonly used too late, is taken in too small quantities, and is not duly persisted in. I have known very extraordinary effects from asses' milk in obstinate coughs, which threatened a consumption, and do verily believe, if used at this period, that it would seldom fail. Asses' milk ought to be drank, if possible, in its natural warmth and, by a grown person, in the quantity of half an English pint at a time, four times, or at least thrice a day; a little light bread along with it, so as to make it a kind of meal."

Asinum lac, subsequently wrote Hooper, "is much esteemed in medicine,” being "preferred to cow's and other kinds, in phthisical cases, and where the stomach is weak, as containing less oleaginous particles, and being more easily converted into chyle." 'Asses' milk has a very strong resemblance to human milk, in colour, smell and consistence. When left at rest for a sufficient time, a cream forms upon its surface, but by no means in such abundance as [on] a woman's milk. Asses' milk differs from cow's milk in its cream being less abundant and more insipid, in its containing less curd, and in its possessing a greater proportion of sugar. The milk of women, mares and asses very nearly agree in their qualities." Vide Hooper, pp. 77, 78 and 498–500.

"in repute'

The Onis, or asses' dung, which was with old Hippocrates, I do not find in any of the last century prescriptions which I have examined. It is perhaps needless to add that the ass was enrolled among the furnishers of bezoar-stones, and that its heels and skeleton were, at least, capable of affording a quantum to our supply of gelatine.

RHINOCEROS.-There is little doubt that the rhinoceros was the producer of a share of the unicorn's and unspecified ivory, dealt with under the heads of Narwhal and Elephant respectively.* It is observable that this brute is, in Pinkerton's edition of "Marco Polo's Voyages" (chap. xxiii.) described

* SCIENCE-GOSSIP, 1890 vol., pp. 153, 154.

as the unicorn, and the name has more or less clung to it ever since. "Our Topsel" (as Izaac Walton calls him), writing in the sixteenth century, remarks that "all the later physicians attribute the virtue of the unicorn's horne to the rhinoceros's horne, but they are deceived by imitation of Isidorus and Albertus, for there is none of the ancient Græcians that have ever observed any medicine in the rhinoceros. The Indians made bottles of their skins wherein they put their lycion, or succum medicatum."

HOG.-The most important article derivable from the swine was that adipose matter upon which his world-wide renown is based. Axungia or Adeps suilla was the name bestowed upon it in its crude state, by men of medicine, and Axungia curata when it had been purified. Adeps suillæ, says Hooper (p. 428), with some apparent disregard for the strict rules of orthography and syntax, "forms the base of many unguents, and is often eaten by the poor instead of butter." To cite its manifold uses, even in medicine, would be quite superfluous. It occurs in nearly every ointment, both for cleansing and healing sores, and for eruptions, ulcers, burns, excoriations, inflammations and ocular complaints. Bate and Salmon also prescribe hog's grease," in combination with other potent agents, for a multitude of skin diseases, and for gout and nodes, "whitloes and felons." For fuller details, vide Buchan, App. pp. 35 et seq.; Bate, pp. 290-3, 402-3, 699, 703, 705, etc.

But piggy was not alone prolific in lard. Just as in trade he provisions us with so many more varieties of meat than his rivals, so in the laboratory he maintained his advantage by the diversity of the drugs he contributed. Salmon (p. 2), in discussing Bate's Aqua antiphthisica, which required an admixture of calf's blood, tells us of other bloods that may equally serve in the same case; but I have found by experience that hog's blood exceeds them all." Another consumption cure is provided by Salmon (p. 581), with six grains of the "Volatile salt of hog's blood."

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Salmon again (p. 247), nourished the emaciated "almost to a miracle," with ten to twelve grains of "volatile salt of hog's flesh" and two drams of sugar, in four ounces of his Tinctura nutritiva, administered three times a day-fasting! For lung complaints he prescribed (p. 597), half an ounce of "water distilled from hog's flesh" in two ounces of syrup of myrrh. "Against phthisicks," moreover, he ordains (p. 597) two grains of the salt of hog's flesh in a dose of "syrup of pepons, pompions or melons ;" and, for consumptive children (p. 596), another two grains in a mixture of snail-syrup, canary wine and milk water.

The afterbirth of a sow (Bate, p. 641), when washed in white wine, dried and pulverised, was a remedy for falling sickness and some complaints incident to women.

Pig's bladder was used to tie mixtures in, to dip them in hot water and dissolve without dispersing

them (Bate, p. 48), and also for dressing wounds. According to Hooper (p. 639), Plunket's cancer remedy should be "laid over the sore or cancer upon a piece of pig's bladder cut to the size of the sore and smeared with the yolk of an egg. The plaster must not be stirred until it drops off, of itself, which will be in a week."

Buchan records (p. 416), a curious use for hog's flesh If deafness proceeds from dryness of the ears, some, instead of oil, put a small slice of fat bacon into each ear, which is said to answer the purpose very well."

Howard (vol ii. p. 970) tells us that "gallings, produced by the wringing of uneasy shoes, are mollified and kept from swelling by the application of the lungs of a swine, warm, to the grieved part," and "for gallings, burns and eruptions of papula, a most excellent plaister is prepared of one ounce of recent swine's fat" and other articles.

The bezoar of the pig requires particular mention Smollet informs us ("Present State," vol. viii. p. 126) that "The countries that lie behind Malacca abound with . . . . hog-stones, reckoned more efficacious than the bezoar-stones," and of this opinion we find ample confirmation elsewhere. Writes Howard (vol. i. p. 333), the hog-bezoar "is found in the East Indies in the gall-bladder of a boar. In figure and size it resembles a filberd, though more irregular. Its colour is not fixed, but most commonly white with a teint of green; it is smooth and shining, and is valued at ten times its weight in gold. It is said to be the best preservative against poison; a sovereign cure for the mordoxé, a kind of Indian plague; admirable against malignant fevers, smallpox, most diseases of women, but promotes abortion if used indiscreetly. To use it, they infuse it in water or wine, till it has communicated a little bitterness to it. The Indians prefer it to the goat bezoar."

"Boar's tooth" was one of the outlandish sources of "first alcalies." Bate, on p. 635, includes it in an antipleuritic powder.

FISH REARING UNDER FAVOURABLE CIRCUMSTANCES.

UNDER

NDER the influence of continuous freshening rains, joined to other favourable conditions, the young Salmonida hatched out last winter have prospered exceedingly this year, at the various FishCulture establishments; and have achieved dimensions, in some cases, almost unprecedented. Since fish-culture was introduced we have been brought into closer communion with many of the fluvial forms; and we are now able to watch their progress from babyhood to maturity, with the result that we understand more and more of the history of their lives. We can tell at a glance how far they are affected by meteorological and other conditions, and