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confidence of success and the supposed magnitude of January. Cold and dry November, expect dry their discoveries. I have received a curious newspaper, December. “ The Future," published at Richland, Shawnee Co., | A difficulty is suggested on reading these indicaKansas, U.S., which promises magnificently and tions, viz., that of finding when the changes come. gives much advice to agriculturists.

In nearly all the cases specified the order for the next I was a boy when London was thrown into a month or next season is, “ As you were.” I suppose spasm of temporary insanity by "Murphy's Weather that we must read all these descriptions of the preAlmanac.” It was all done by one lucky hit. Any- ceding period as intended for exceptional weather, body may make an almanac and predict the weather and that such weather usually shades off gradually, for each day in the year, and be right more frequently while the more decided changes more commonly than wrong, by simply taking the averages from follow average weather. meteorological observations and predicting accord I am glad to find among the papers read in Section ingly; but Murphy was bolder than this. He pre. B (Chemistry), one by Professor Odling, which has dicted that a certain day early in the year would be the merciful intent of relieving us from some of the phenomenally cold, and it was so ; 28 degrees below structural names which are daily poured upon the freezing in Hyde Park. Then followed a rush to unhappy student of organic chemistry. Every plant buy the almanac, and a ridiculous excitement. Songs that has an odour, or has a flavour, or contains any were sung in the streets, and wild stories were told thing that has any special property, may be tortured of the magnetical and electrical discoveries of the until it yields some substance with real or imaginary great meteorological Murphy.

special composition and properties, and every such In spite of all our meteorological observatories and substance may be physicked with strong acids or observations, we are still unable to make any far strong bases, or chlorine, iodine, bromine, &c. &c., forward predictions of weather beyond stating prob and forced into some sort of combination with these ; able averages. Storm warnings are fairly reliable, and the compounds thus formed may unite with other but these and the rest of the daily forecasts of the compounds, and thus on, ad infinitum. Millions of Meteorological Office are not exactly predictions. millions of such things may be concocted, then They are statements of atmospheric movements that analysed, then formulated, and then named according are proceeding in certain directions, and which, if to their imaginary molecular constitution. Now that they continue, will reach certain localities a few we have hundreds of young aspirants for chemical hours later. They do commonly continue as antici fame who devote themselves to such mixing, and pated, but not certainly. About eighty per cent. of messing, and analysing, and naming, the torrents of the forecasts are fulfilled, and the rest are failures. papers poured into the learned societies combine to

A really valuable contribution to weather-wisdom produce a flood that is simply maddening, and would was read at the last meeting of the British Association drive all our chemists into lunatic asylums, but for a by Dr. Courteney Fox, “On Some of the Laws protecting providence which has ordained a beneficent which Regulate the Sequence of Mean Temperature law that operates with stern rigidity; viz., that and Rainfall in the Climate of London.” These laws nobody but the author and the printer ever reads are induced from observations extending over the these papers. , I pick up at random the two last last seventy years. They are necessarily empirical,

numbers (October and November) of the “ Journal of i.l., all mere generalisations of average fact, not the Chemical Society,” and find among the abstracts deductions from necessary causation. Dr. Fox finds of papers on Organic Chemistry more than a hundred that if a spring or a summer be very cold, the suc of these new substances discovered during each ceeding season will be cold, and that warm autumns current month. This has been going on for years, succeed very warm summers. It is very rarely that and may go on for ever, if the supply of ordinary a dry August is followed by a wet September. A laboratory aspirants is maintained. As an example very wet and cold summer is usually succeeded by a of the sort of names which Professur Odling desires cold autumn. If January, April, June, July, August, to reform, I will quote two or three from one of the September or December are very cold, the succeeding numbers of the journal above named. “Orthochloromonth will probably be dry. Very warm January, carbonylphenylorthophosphoricdichloride," obtained by expect a dry February. The next month following R. Anschütz, and re-named as above, its original name a very warm June, July, or August will be warm. given to it by Couper, trichlorophosphate of salicyle, Very wet January, March, or April, usually fol. being too short (page 1062). “ Tetrachloroquinonelowed by a warm month. Warm and wet November metanitraniline," obtained in black crystals by M. and December, wet month to follow. Warm and Niemeyer, together with a dozen of other chemical wet January, expect a warm February. A warm cousins (page 1066). E. Bamberger and S. C. month usually follows a warm and dry June or July, | Hooker present us with several of their new-born and a wet September follows a warm and dry August. chemical babies, among which is one that bears the Cold and wet July and August, expect cold month pretty name of “hydroxyisopropyldiphenyleneketoneto follow. Cold and dry December, expect cold carboxylic acid,” which is described as “a strong acid containing only one carboxyl group" (page 1070). | six-sided teeth are arranged in seven rows (fig. 181), When its younger brothers, containing several carboxyl the median row consisting of much elongated plates, groups are born, and named according to their more and the three lateral rows on each side, of small complex composition, the result may be imagined. | hexagonal plates. About eleven species are recorded* These are all culled from pages 1062 to 1070 of the from the London Clay, and the Bracklesham and October number. I have marked others in the Barton beds, the most important being M. Toliapicus November number, but in mercy to my readers will and M. Dixoni, and associated with them are examples not quote them.

of caudal spines. The dentition of Ætobatis, also Professor Odling proposes to supply empirical found in the same strata, differs from that of Myliobatis names instead of these, justly observing that “the in consisting only of a single row of plates (fig. 182). primary purpose of a name is undoubtedly to designate About six species of this genus have been described and not to describe.” In “ The Gentleman's Maga from the English Eocenes, but the fact that the teeth zine" of October, 1880, I illustrated the result of this principle of naming a thing by a description of its composition, by applying it to the case of our familiar Christmas-pudding, Suetofloureggcandied peelraisinspicecurrantsconglomerate, would thus be its pretty little title.

As the primary object of 99.9 per cent. of the researches which produce these violent neological

Fig. 181.--Teeth of Myliobatis. outbreaks is to establish the reputation of the analyst, why not carry out this purpose more effectually by bestowing upon these new concoctions the names of their parents, with a distinctive prefix? Thus Smith's chemical first-born might be named Alpha Smith, his second Beta Smith ; then Gamma, Delta, and on to Omega Smith. After this Alpha A. Smith, Alpha B. Smith, &c., to the end of the Roman alphabet. This would supply 24 X 26 = 624 names, after which numerals might be used, 625 Smith, and so on to the required number of thousands.

Fig. 182.-Straight teeth of Ætobatis.

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CHAPTERS ON FOSSIL SHARKS AND

RAYS.
By Arthur Smith WOODWARD.

v.

MYLIOBATIDA. COME of the largest and most pelagic of the living » Batoidei are included in this family, and fossil remains of at least three genera are not uncommon in the Tertiary deposits, both of this country and the Continent. One of their most characteristic features, and that which is of greatest interest and importance to the palæontologist, consists in the nature of the dentition. The mouth is armed with a number of flat crushing plates, often united firmly together by sutures and varying in arrangement in the different genera ; they are placed in successive transverse series, and as the front rows become unfit for use, they fall out of the mouth, being replaced by new ones from behind. These dental plates, together with specimens of the barbed spine fixed upon the tail of some forms, constitute all the known fossil evidence, and are met with in Eocene strata at Sheppey, Bracklesham, and Barton ; in Miocene at various Continental localities ;, and in the Pliocene Crag of Norwich. The type-genus is Myliobatis, in which the

of one jaw are sometimes nearly straight (fig. 182),
while those of the other are considerably arched
(fig. 183), renders the specific determination of de
tached plates somewhat uncertain. Zygobatis (fig. 184)
is another form, referred to the living Rhinoptera by
Dr. Günther, and characterised by the disposition of
the dental armature in seven longitudinal rows, as in
Myliobatis ; here, again, the plates are six-sided, and
also united to form a tessellated pavement, but besides
the relatively great breadth of the middle series, the
two adjacent rows are also considerably elongated
in a lateral direction, and there are thus only two

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rows on each side that comprise approximately true | above, are merely placed temporarily in the respective hexagons. 2. Woodwardi (Agassiz) occurs in the positions assigned to them upon somewhat slender Norwich (Mammaliferous) Crag of Norfolk, and evidence, but the relics to be considered in the other species are known from the Swiss Molasse present section are even less satisfactory in the (Miocene).

features they display, and can thus only be relegated

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and as it is the custom to restrict the term to those most distinctive feature of the spine is the absence of spines whose precise relationships are indeterminable, posterior denticles. in consequence of their never having been found in The Old Red Sandstone and Devonian—at least association with definite fragments of the rest of the in this country-yield no ichthyodorulites of imfish-structures, to which they originally belonged, portance, but almost all divisions of the Carboniferous the number of forms included in this category has are replete with examples of the greatest interest. been considerably reduced by the progress of research. The largest forms hitherto discovered are met with Among those removed, for example, are the Devonian in the Carboniferous Limestone, Phoderacanthus Parexus (of which an outline is given in fig. 185), the grandis, * from Bristol, probably attaining a length of Carboniferous Ctenacanthus and Pleuracanthus, alluded no less than three feet. Among others, we may to in previous articles, the Jurassic Leptacanthus, now especially refer to those known under the names known to belong to a Chimæroid (Ischyodus) and of Gyracanthus, Orthacanthus, Acondylacanthus, many others. But there are still a large number | Lepracanthus, and Erismacanthus. that can be referred to no very definite place, and Gyracanthus is a genus first established by Agassiz, though they may not all be truly Selachian-as is, and more completely elucidated since by the researches quite probable, and has proved to be the case with of Hancock, Atthey, and Traquair, upon a much Parexus and Leptacanthus just mentioned-it will be larger series of specimens : it ranges throughout the convenient to group the whole together until our whole of the Carboniferous strata, though not yet information becomes more complete. Some forms known to extend either above or below, and is soappear to have been placed in front of dorsal fins (as called in allusion to the peculiar appearance of the shown in the drawing of Spinax, Vol. XX. p. 172, or spine produced by the arrangement of the ornamentain fig. 185, a); others were almost certainly pectoral tion (fig. 187). The ichthyodorulite is characterised by or ventral fin-spines and perhaps situated like those its very slightly compressed form,-almost round in of the curious Acanthodian fishes (fig. 185, 6); and

transverse section,-by an extensive internal cavity, others, again, may correspond to the little triangular and a long base of insertion; some examples are of dermal scutes (fig. 185, c) that are also to be found considerable size, attaining a length of sixteers or in pairs in the same primitive tribe. Nearly all are eighteen inches, and almost all that are referable to ornamented on the external surface with variously | adult fishes exhibit a long worn surface at the tip disposed ridges and tubercles, often enamelled, and ) (fig. 187, a), evidently due to constant friction with the portion embedded in the tissues of the body-the the bed or sides of the water in which their original extent of which varies considerably in the different possessors lived. It is further noticeable that-informs—is usually smooth or finely striated. More stead of being symmetrical-all these spines are over, all agree in being destitute of any articular

distinctly “ lefts ” and “rights,”-a fact suggesting facettes at the lower end, thus indicating the cartila that they occurred in pairs, and taken in conjunction ginous state of the skeleton with which they were

with the wearing of the tips, doubtless indicating once connected ; and the presence of an internal

that they were placed in front of pectoral or ventral cavity, opening lengthwise behind and below, or fins. Messrs. Hancock and Attheyt believed, also, simply in a hole at the base, is also evidently a that they had discovered a few symmetrical spines of constant character.

the same type, and hence regarded the latter as The earliest of these dermal weapons hitherto dorsal ; but Dr. Traquairt has more recently shown described is the little Onchus (fig. 186) from rocks of that there is no unquestionable basis for such a conUpper Silurian age. With the exception of Scaphaspis clusion, and considers it to have been founded upon ludensis, from the Lower Ludlow of Leintwardine imperfect materials. Associated with the ichthyo. (Shropshire), and the doubtfully piscine conodonts, | dorulites, there often occur patches of small dermal it is the oldest evidence of the existence of vertebrate tubercles, and occasionally also curious triangular life yet known. In Britain, it occurs in the celebrated bodies, once looked upon as the carpal cartilages of Ludlow bone-bed, and in the passage beds between Gyracanthus. These are hollow and open at the the Silurian and Old Red Sandstone strata of the base, with a roughened surface destitute of any same area, and quite lately, spines of a similar type ornamentation, and, from a study of their microhave been recorded* as occurring in beds of a slightly scopical structure, Dr. Traquair has determined that earlier date in America ; but the remains originally they are truly dermal appendages. The number on ascribed to this genus from strata of the carboniserous species already described from British rocks is about period appear, from more recent discoveries, to

seven, and the best known appear to be the belong rather to such forms as Physonemus and G. tuberculatus and G. formosus, of which the coal Ctenacanthus. The external surface is characterised by thick and smooth longitudinal ridges, and the

* J. W. Davis, Trans. Roy. Dublin Soc., Ser. 2, Vol. I. (1882), p. 534, pl. lxv. Since description, the original specimen of this fine ichthyodorulite has been presented by Earl Ducie

to the British Museum, where it is now to be seen. * E. W. Claypole, Quart. Journ. Geol. Soc., xli. (1885), + Ann. and Mag. Nat. Hist., [4] I., 1868, p. 368. P. 61.

I Loc. cit., [5] XIII., 1884, pp. 37–48.

measures of Northumberland have yielded a most | morning. He will rise at 5.27 in the morning on extensive and instructive series, now in the Newcastle the 3rd, and about thirty minutes earlier each sucMuseum.

ceeding week. The spines included under the name of Oracanthus There will be an occultation of Uranus on Dec. (Agassiz) are of a very curious and problematical Ist. The planet will disappear at 5 o'clock in the nature; they are more or less triangular in shape morning and reappear at 6 hrs. 9 mins. There will (fig. 188), sometimes twelve or fourteen inches in also be occultations of K Virginis, u Piscium, T Leonis, length, and ornamented externally with transverse and o Virginis, but these stars being all about the rows of blunt tubercles or irregular ridges, but 5th magnitude their occultations will possess little exhibiting no broad smooth surface for insertion in interest. the soft tissues of the body. All possess a large It is a highly interesting question how quickly the internal cavity, opening at the base, and seem to new star in Andromeda appeared, that is whether it have been originally arranged in pairs, for (like was first visible to any observer faintly and then Gyracanthus) they are invariably “lests” and became brighter and brighter until it attained its “rights,” and some show traces of terminal abrasion. fullest magnitude, which was probably about the 7th O. Milleri (fig. 188) is the species to which the or Sth of October. For my own part I should think majority of the British fossils are referred, and with it it must have almost flashed into existence at once, Mr. J. W. Davis has recently* associated a number of because the great nebulae are constantly watched by dermal plates of various forms, on account of the so many observers that I do not think it couru have close resemblance of their ornamentation; if the been present for more than two or three evening, latter are correctly so placed, Oracanthus must have without being seen. Mr. Benjamin Kidd, of Bramley, possessed a strong covering of armour-at least, in Surrey, appears to have seen it at least two days the region of the head, but any satisfactory evidence before any other observer, as he noticed it on the as to the facts is at present wanting. The genus Ist of September, though he did not write to Greenappears to be exclusively confined to the Lower wich Observatory until the 3rd of September, because Carboniferous, the most abundant remains being he waited to see it again. those of O. Milleri just mentioned, from the Car Mr. Frank McClean, of Rusthall House, Tunbridge boniferous Limestone of Bristol and Armagh, while

Wells, informs me that, seen with his 10-inch others named O. pustulosus are sometimes met with achromatic, the star on the ioth of November was in the equivalent beds of Oreton, Shropshire.

scarcely brighter than many of the surrounding (To be continued.)

small stars, that is, it had waned probably to about the 12th or 13th magnitude.

I shall be glad of any further information on this

subject. ASTRONOMY AND METEOROLOGY FOR

In No. 2690 of “ Astronomische Nachrichten,” the THE MONTH.

attention of observers is called to the SearchingBy John BROWNING, F.R.A.S.

Ephemeris for the periodic comet of Olbers of 1815,

contained in Nos. 2613 and 2614 of that periodical. V ENUS will be an evening star throughout the

Its perihelion passage is calculated to occur on the month in Capricornus. She rises about

17th of December, 1886, with an uncertainty, one eleven in the morning, souths about three in the

way or another, of 1.6 year. During its apparition afternoon, and sets at times varying between 7.12

in 1815 this comet remained a telescopic object. and 8.3. Mercury will be an evening star until the

Its orbit was calculated by Dr. Olbers. 20th, and a morning star after that date, rising at

The sun will enter Capricornus at 3 o'clock in the times varying between 9.42 A.M. on the 3rd, and

afternoon on the 21st of December, when winter will 6.21 on the 31st, and setting at 5 P.m, on the 3rd

commence. and 2.49 on the 31st. Mars will be in Leo, and

The month of November was unseasonably cold, will be in conjunction with the moon on the 27th at

being about 5 degrees Fahrenheit below the average, 9 o'clock in the morning, rising at 10.50 P.M. on the

and there were several night frosts. 17th, southing at 5:33 A.M., and setting at o hr.

The average temperature for London in December, 13 mins.

taken from observations of a period of fifty years, Jupiter will be in Virgo, and will be in conjunction

is 40°, while at the Land's End it is 46°, the difference with the moon on the 28th at 9 o'clock in the

being due to the action of the ocean. The average Inorning. He will rise on the 3rd at i hr. 18 min.

rainfall for the month in London is between two and morning, south at 7 hr. 22 min, in the morning, and

three inches. set at i hr. 26 min. in the afternoon. Saturn will be almost stationary in Gemini, and

M. ROBIN, the celebrated French histologist, author will be in opposition on Dec. 26th at 10 in the

of “ The Natural History of Vegetable Parasites in * Trans. Roy. Dublin Soc. [2], 1. pp. 525-531, pls. Ixii-Ixv. Man and Animals,” has just died at the age of 64.

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