despise the prevailing exaltation of mere linguistic grindery.

In the same magazine is a letter from Mr. E. C. Mason, of Madison, Wisconsin, stating a fact which refutes the widely prevalent notion- I may almost say superstition-that many of the lower animals are endowed with marvellous powers of predicting the far-ahead weather. In America the musk rat is one of these supposed meteorologists. It is there believed that when he builds his winter quarters lightly, he does so because he is inspired with foreknowledge of a mild coming winter. Last autumn, the musk rats of Wisconsin built their houses "exceptionally light and unsubstantial." The winter was severe, and the rats perished exceptionally. The actual reason for the flimsy building was that the autumn was unusually mild, and the rats simply adapted their present proceedings to present weather.

This American delusion, however, is a very mild one compared with that which still prevails here, concerning the complex intelligence, foresight and benevolence of the holly, which is seriously credited with developing an extra supply of berries on the approach of a hard winter, in order that the birds, especially sparrows, shall be provided with food when the snow covers the ground.

I need scarcely add that anybody who knows how to observe facts accurately, and record them fairly, may refute this absurdity. The development of the berries, like the proceeding of the rats, is a result of past and present weather, with possibly some other past and present conditions co-operating.

Before closing the above quoted magazine, I must borrow from it an amusing story of medical evidence, given in a trial for damages. A physician, called as witness, stated that the plaintiff was suffering from the remote effects of an injury to the vaso-motor system of nerves, and would in time become insane. In cross examination, the doctor was asked whether he was acquainted with the works of Grosse "On Recent and Remote Effects of Head Injuries," Lanery on "Injuries of the Head," Leymaher "On the Subsequent Effects of Nervous Shock," and Carson "On the Surgery of the Head." The doctor affirmed that he had read these books, and that his library contained them all. The opposing counsel then called to the witness box a clerk from his office, who testified that all these works were fictitious, and that he had invented the titles in order to expose the doctor's ignorance.

The ruling machine of Nobert is now in London, has been purchased by Mr. Frank Crisp, and was exhibited at a recent meeting of the Royal Microscopical Society. I remember when a micrometer slide for a microscope ruled to rood of an inch was an object of curiosity, and rather costly. With Nobert's machine of an inch is attainable. Remembering that the divisions of gave to the strip of glass the appearance of being ground where they crossed, the

lines and spaces being separately invisible to the naked eye, this exploit of dividing the invisib'e divisions into 112 parts appears impossible. The difficulty does not consist in moving the point, or stage holding the glass, accurately through the small distance. An ordinary driving engine constructed on the principle of those of Ramsden and Parsons, which were in active operation 50 and 60 years ago, does this easily, but the two other necessary elements, a point sufficiently fine to cut a line less than 100000 of an inch thick, and a surface of glass capable of receiving such a cut presented problems which Nobert overcame. The cutting point was of course that of a diamond, worked to a knife-edge, either by grinding, or chipping, or slitting.

Everybody has read of the wondrous rapidity of the growth of Arctic vegetation. Now that summer excursions round the North Cape to the Varangerfjord are running weekly aud even oftener (see "Belgravia" of June last) anybody who has a month's holiday at about midsummer may witness it and see the midnight sun, &c., at less cost than spending the time in English hotels. On my first visit to Norway, Hammerfest was the ultima thule of steam packets, but even on this short journey, the difference between the aspect of the country, in the course of ten days between going and returning was marvellous, though I did not repeat the experiment of the American tourist who tells us that by placing his head on the ground he could hear the grass growing. Not only is the vegetation stimulated to excessive rapidity by the continuous daylight, but the leaves and seeds of the plants are larger and heavier. Schübeler has lately analysed these larger seeds (see Biedermann's "Centralblatt für Agricultur u. Chemie," 1884, p. 860), and finds that the extra weight is not due to nitrogenous matter, as this remains unaltered. Plants that produce white blossoms in other places frequently have violet flowers here. Perfumes are remarkably developed.

The best time for witnessing the rapidity of vegetation in Arctic Norway, is about the first week of July. Starting from Trondhjem, on, or a little before, the first of the month, the northward trip displays snowclad regions, which on the return journey a fortnight later have become so transformed as to be difficult of recognition.

A very simple method of testing the quality of compressed or "German" yeast, is given by O. Meyer (Biedermann's "Centralblatt,” 1874, p. 792). A small piece of the yeast is placed in water at the temperature of 25° Cent. (77° of our thermometers). If the yeast is in good active condition it will rise to the surface in one and a half to two minutes, if of poorer quality, in about five minutes. Bad yeast will not rise at all.

Having devoted a whole chapter of my "Chemistry of Cookery" to the subject of "malted food," which until I wrote about it in "Knowledge" had been

sadly neglected, I am glad to see that its importance is becoming recognised by "the faculty." In the "Lancet" of April 4th, Dr. J. Milner Fothergill commences a communication on the subject by saying that "Malt as food has a great future before it." So said I, and further practical study of the subject not only confirms my original expectations, but greatly extends them. Dr. Fothergill naturally looks upon the subject from a physician's point of view, and describes the value of malt flour as a supplement to the food of dyspeptic patients. I am by no means a dyspeptic, quite the contrary, troubled with overnutrition and its bulky consequences, but nevertheless I have found the use of malt as an addition to every kind of food containing farinaceous matter very advantageous, and am receiving communications of gratitude from strangers who have followed my advice given in "Kuowledge," and repeated in the volume above named.

So much having been said concerning the value of malt as cattle food during the agitation for the repeal of the malt tax, we might have supposed that human beings should have been considered at the same time, but instead of this the idea of using it ourselves is almost a new one. The cost has shut out the cattle, but it need not exclude us, though I am sorry to say that the price I have had to pay for malt flour hitherto is simply ridiculous. It is at present regarded by vendors as a fancy article, and retailed at perfumery rates of profit. This, I hope, will right itself by the wholesome operation of competition when it takes its place as a primary kitchen requisite. I have already brandished a rod of terror in the face of one shopkeeper. I have threatened him with William Whiteley and the Stores.

Another difficulty is kitchen prejudice. My pet experiment for demonstrating the "potential energy resident in malt is to make a portion of oatmeal very thick or pudding-like; then to add a spoonful of dry malt flour to this at the temperature of about 140° to 150°, and stir the mixture, when, lo, presto! the thick pudding, instead of further thickening by the dry addition, gradually becomes thinner and thinner till quite sloppy. This effect, so much like that produced by adding water is naturally supposed by the orthodox cook to be of the same nature; a dilution or 66 taking out the goodness." When cooks are sufficiently educated to understand that all their farinaceous thickenings must be reduced to watery solutions before doing the work of nutrition, they will appreciate the importance of performing this necessary first stage of digestion in the kitchen.

I have recently made an interesting visit to the works of Messrs. Burrowes & Wellcome, where "malt extract is prepared on a large scale, by boiling an infusion of malt in vacuo, so as to extract and concentrate the diastase. The result is a honeylike syrup of maltose, &c., the resemblance of which to the honey of a Swiss breakfast-table has suggested

another simple mode of obtaining malted food. I spread it like honey or jam on bread or toast, with or without previous buttering. A very thin film is sufficient to supplement the work of the salivary glands in the manner described in the book above named. To those who take hurried breakfast, and rush off to business immediately after, this is a matter of vital importance, however robust they may be at present. To supply this and other similar every-day domestic demands, the extract of malt must become much cheaper than it is now, as it probably will, when it becomes a grocery commodity demanded by the hogshead like sugar, instead of a pharmaceutical product supplied in bottles.

I attended the lecture of Mr. Fletcher at the Parkes Museum. His object was to show that we may, if we choose, do away with the nasty practice of burning coal in dwelling houses, and thereby not only griming everything indoors, but also rendering our towns and cities hideous by smoke and brown fogs. This is to be effected by using gas fuel for all domestic purposes. If the gas companies were compelled, as they may be, to fulfil the conditions of their charters by supplying the public with gas at cost price, plus the maximum profit allowed by their charter, this wholesale reform might be effected with a considerable economy. Mr. Fletcher showed us that not only domestic heating may be economically effected by gas, but that bakeries, manufactories, &c. may be similarly served by means of gas, plus gascoke. He has proved by practical experiment in his own works, that with a properly constructed furnace, a steam boiler of the cheapest form may be made to do better duty with coke, and last much longer, than the complex and more expensive boilers fired in the usual manner with flaming coal. But the coke must be mixed with brains. The users must understand that the coke fire does its work by radiation almost entirely, while the flame acts chiefly by convection. Therefore, the furnace must be modified accordingly. It was evident from Mr. Fletcher's description of his furnace that its efficiency depended on this principle, though he did not thus explain its rationale.

A

SOME FERNS OF HONG-KONG.

By Mrs. E. L. O' MALLEY.

SHORT account of some of the Hong-Kong ferns may be interesting to the general reader. There are few persons who take no notice of the works of nature, and the study of ferns constitutes one of the simplest branches of natural science. The material for such a study meets us everywhere, and there is hardly a corner in the world where ferns are not found. In the northern regions beyond the Amur, in Scandinavia, and amidst the snows and long winters of Labrador ferns flourish, when flowers can only show their tender tints and disappear.

Countries subject at times to extreme cold and long drought are the least favourable to their growth. In the temperate zones they abound everywhere; but it is in the deep shade of tropical forests, where the air is densely saturated with moisture, and the sun's rays can never penetrate, that these exquisite plants luxuriate most freely. Nay, if we go back to the beginning of creation, before flowers, before trees, long before animal life had commenced, we find ferns and their allies, the club-mosses (Lycopodiaceae)

we fear "fragrant" no longer,* at least not deliciously so), cannot be compared in point of size and grandeur with our king of British ferns, O. regalis. But there are sufficient points of resemblance for any acquainted with one, to recognise the other. The clusters of spore-cases occupy the centre of the frond, narrowing and altering it in appearance. The frond is simply pinnate, and often deeply serrate, usually from 2-3 feet high. The colour is bright green with a firm, shiny, erect appearance, differing in this from the

Fig. 69.-Lygodium scandens, Sw.

Can we fail to take an interest in them? And can our interest be satisfied until we have bestowed some attention upon the structure and classification of the different species we meet with in our daily walks ?

The following notes may be of assistance to those who wish to know something about the common ferns growing in the neighbourhood of Victoria and the Peak.

Gen. I. OSMUNDA, Linn.

(0. Javanica, Blume.)

The species we shall find in many water-courses and along the banks of rocky streams (some of them

Gen. II. LYGODIUM, Sw.

(Creeping or Climbing Fern.)

There are three species of lygodium to be found in Hong-Kong, but in Lygodium Japonicum, Sw., we have the commonest, if not the loveliest, fern in the island. Examine the sori all round the edge, like the joints of a cog-wheel. How beautifully the seedcoverings are plaited, or laid like the tiles of a roof one upon the other, each tiny tenement containing one capsule or spore-case, which in its turn holds numerous spores (or seeds), almost invisible to the naked eye! The leaves are either in pairs or else pinnate (i.e. with pinnæ or plumes like a feather), the segments or divisions of the frond often numbering from 5-10. There is no need to say that this fern is a climber. It creeps up anything it can catch hold of, and often attains in this way to a considerable

height. A word about it in other lands may perhaps be interesting. Miss Gordon Cumming says: "Loveliest of all are the delicate climbing ferns, the tender leaves of which, some richly fringed with seed, hang mid-air in long hair-like trails, or else, drooping in festoons, climb from tree to tree, forming a perfect net-work of loveliness. It is a most fairy-like foliage, and people show their reverence for its beauty by calling it the Wa-Kalon, or God's Fern."* For superstitious reasons also the natives encourage it to grow up their walls and door posts. Lygodium Japonicum has a pinnate frond; in L. scandens, Sw., the divisions are in pairs, broad at the base and narrowing to a rounded apex, and of a more delicate texture than the last, not nearly so common. dichotomum, Sw., has fronds 8-10 inches long.

Gen. III. GLEICHENIA, SW.

L.

(Called in some places "Comb Fern.") Gleichenia dichotoma, Willd., is abundant, not only in Hong-Kong where it is cut down for bedding for cattle, but in the tropics all round the world. If it were not for its trailing propensities, it might be compared to the brake of our native land; it is also not unlike this fern in roughness of texture, although quite apart in the position which by the formation of its seed it holds in fern-classification. The spore-cases have no covering, but are lightly set in a white flour-like substance in loose groups of 2, 3, 4, or 5, under the leaf. The fern is not very often met with in seed. The arrangement of the long, stiff, pinnate leaves is an easy distinguishing feature, as they grow in pairs, or forked (hence the name di-chotoma, 2 cleft), each fork resulting in another fork and so on, until the long straggling branches form in some countries an impenetrable jungle, too thick for a horse to break through, and mounting 6, 8, or 10 feet high on boughs of trees, low shrubs and underwood. It has been called the "Comb Fern," as the leaves when dry are stiff and like the teeth of a comb.

(To be continued.)

FOR some years past, attempts have been made (without much success) to acclimatise the tea plant in Italy. The Italian Minister of Agriculture has determined to act upon the suggestions of Professor Beccari, who has been investigating the subject, and to procure some plants from the coldest provinces of Japan, as well as some from the province of Novara in Italy. The Thea Sinensis has been grown to some extent in the open in Italy, and Professor Beccari thinks there is no reason why tea should not succeed there, under proper management in procuring plants and seeds and in the conditions under which they are cultivated.

"At Home in Fiji," by Miss G. Cumming.

CHAPTERS ON FOSSIL SHARKS AND RAYS.

BY ARTHUR SMITH WOODWARD,

OF THE BRITISH MUSEUM (NATURAL HISTORY).

UNTIL

IV. CESTRACIONTIDE.

NTIL quite recent years, the family of Cestraciontidae was regarded as including all the varied forms now grouped under the Orodontidæ, Psammodontidæ, Copodontidæ, Cochliodontidae, and Petalodontidæ, and thus its zoological and palæontological signification has been considerably altered of late. The most modern researches seem to show that Acrodus and Strophodus are the only important extinct genera that can be referred to it with certainty, but Ptychodus is also placed here by most palæontoists, although it appears much more nearly allied the Rays, judging from the little that is known about the arrangement of its teeth.

Reference has already been made to the dentition of Cestracion, the only existing genus of this family, in the account of the Cochliodonts (vol. xx. p. 270). The diagram (fig. 71), however, will give a more correct idea of the aspect of the jaw: there is much more variation in the dental forms in different parts of the mouth than is to be observed among those sharks with laniary teeth, such as the Carchariidæ and Lamnidæ, and the hindermost are adapted for crushing food, while those at the symphysis are distinctly conical and prehensile. Several rows are in function at a time. It is a noteworthy fact, also, that Cestracion has defensive weapons in the form of dorsal fin-spines, while the members of the families just alluded to are destitute of these, their sharp piercing teeth being a sufficiently formidable armature. Only four species of Cestracion are described by Dr. Günther, in his British Museum Catalogue, living off the coasts of Japan, Australia, California, and the Galapagos Isles, and no undoubted fossil remains of the genus have hitherto been recorded.

As in the case of Hybodus, all the more perfect specimens revealing the structural characters of Acrodus have been obtained from the Lower Lias of Lyme Regis. There have been discovered some beautiful examples exhibiting the arrangement of the dentition, others showing the two dorsal spines in association with scattered teeth, and others indicating that this genus possessed the four remarkable cephalic spines so characteristic of nearly all, if not all, the species of Hybodus. The most typical teeth of Acrodus (fig. 73) are distinctly of the Cestraciont form, and usually differ considerably from those occupying similar positions in the mouth of Hybodus, being quite flat or only slightly rounded, and ornamented with very fine ridges and furrows radiating from a more or less central longitudinal line; the dentition of this genus, too, varies more on different parts of

the jaw than in the typical species of Hybodus, and there are some dissimilarities in microscopical structure. The symphysial teeth approach a conical form, and there is sometimes a slight indication of lateral or secondary cones. It must be remarked, however, that some species, such as A. Anningia (fig. 84), are quite on the borders of the two genera, and the ornamentation on a few of even the most characteristic Acrodont teeth (fig. 74) is suggestive of . their close relationship to those of the true Hybodont type.

The dorsal spines of Acrodus, unknown to Agassiz, were first described in the "Geological Magazine, twenty years ago, by Mr. E. C. H. Day. In this elaborate paper, he points out how nearly they resemble those of Hybodus, and is unable to discover more than two points of difference between them. He endeavours to show that, in spines of the latter genus, the double row of posterior denticles is fixed upon a somewhat prominent ridge, as seen in the section (fig. 75), while in Acrodus, the back of the spine is comparatively flat (fig. 76); also, that the denticles themselves are fewer and stouter in Acrodus, than in Hybodus. But it must be remembered that, since the date of these studies, much more valuable material has accumulated, and it is questionable whether, when a large number of specimens, such as are now available, are examined, many intermediate gradations will not be found. The object of Mr. Day's paper is, indeed, to prove that Hybodus and Acrodus are closely allied, and that the only differences between them are merely in degree and not in kind; and he concludes a very careful discussion of their characters by suggesting that, according to their dentition, the Hybodonts and Acrodonts might be regarded as forming a single group, divisible into three sections :-"the first, with very elongated cones, represented by H. basanus; the second, with the cones more obtuse, by H. Delabechei; and the third, almost or altogether wanting conical elevations, by A. nobilis." How far these conclusions are to be accepted, future research must decide.

Species of Acrodus range from the Triassic to the Upper Cretaceous strata, inclusive. The Continental Muschelkalk has yielded A. Gaillardoti and others, and the Rhætic of Devonshire is characterised by the little A. minimus (fig. 77). A. nobilis (fig. 73) and A. Anningia (fig. 84) are the most important species of the Lias, being found chiefly in the lower divisions, and not so abundantly as the remains of Hybodus. A. leiodus and A. leiopleurus occur in the Stonesfield Slate; and two species, A. Illingworthi and A. cretaceus, have been described† from the English chalk.

The genus Strophodus is not quite so well known as that just considered. No certain information has hitherto been obtained concerning any feature in its

"Geol. Mag.," 1864, vol. i. pp. 57-65.

+ Dixon's "Geology of Sussex," 1st edit., 1850, p. 364.

organisation beyond the dentition,* and only one specimen affording a definite clue to the arrangement of the teeth appears to be yet known to science. This beautiful example is preserved in the Oolitic Caen Stone, and was described by Sir Richard Owen in the 66 Geological Magazine" for 1869. It exhibits about sixty teeth in situ, and is represented in fig. 72. As regards the arrangement of the different dental forms, it bears a close resemblance to the jaw of Cestracion, but differs from the living genus in the same respect as does the jaw of Acrodus, namely, in the symphysial teeth being much fewer and relatively larger. There are two principal rows of crushing teeth (fig. 72, a, b), as in Cestracion, and there are likewise indications of some posterior rows of smaller and somewhat elliptical teeth (ib., e); but, instead of nine rows occupying the space in front of the principal series on each side, only three are to be observed (ib., b, c, d), and no median azygous row is present. The teeth themselves, when isolated, are readily distinguished from those of Acrodus by means of their surface-ornament, which consists of reticulate markings, but a glance at the figure of the Caen specimen is sufficient to show the extreme difficulty of determining the species of such detached fossils.

Strophodus ranges from the Upper Permian to the Chalk, inclusive. It is represented in the Kupferschiefer of Germany by S. arcuatus, and at least one species is also found in the Triassic Muschelkalk. S. magnus is characteristic of the Lower Oolites, and other so-called species (S. tenuis, &c.) likewise occur upon the same horizon; S. favosus is the name of some small teeth (fig. 78) from Stonesfield. The Middle and Upper Oolites,-particularly the Oxford and Kimmeridge Clays,-yield the well-marked form, S. reticulatus (fig. 79), which is easily recognised by the prominence of its ornamentation: of this species we know more than any other, except S. medius (fig. 72), a large number of teeth having been found associated in the Kimmeridge Clay of Shotover, and described by Agassiz in his great work on the "Poissons Fossiles." The Cretaceous series contains the last traces of the genus, so far as is yet known, and only two forms appear to have been recorded from this group; one is S. sulcatus, from the Greensand of Maidstone, and the other the very rare and curious S. asper (fig. 80) of the Chalk.

Ptychodus is an essentially Cretaceous genus, and has not hitherto been met with in rocks of any other age, either in the Old or New World. Nothing beyond the dentition is known with certainty, although Agassiz, in his original description of this shark, associated with the teeth certain peculiar elongated fossils which he thought might be the

* It has been suggested that the spines known under the name of Asteracanthus really belong to Strophodus; but absolute proof is at present wanting, and we shall thus reserve their consideration for the chapter on "Ichthyodorulites."