meteorology still impressed with the idea that, with a correct knowledge of what has been, we may be able to form an opinion of what is to be. It seems to us by no means improbable that with more accurate information, such as this now being stored for future use, we may before long arrive at the power of foretelling the general character of seasons, in regard to their being wet or dry, hot or cold, stormy or gentle; but we see no reason to believe that any amount of study of the past will ever enable us to predict in detail for any length of time in advance, though it may and must lead us to a better capability of rightly interpreting the atmospheric changes going on, of detecting them at their earliest beginning, of judging their probable effects, and thus of extending the period for which storm warnings" may be made available. With increased experience new power will be gained, new methods will be learned and proved. Even now, the spectroscopic observations by Commander Maclear, to which he called our attention in these columns only a few weeks ago, seem to point hopefully towards a new path in meteorological research; for it is not only in the widely different climate of the Bay of Biscay, the Red Sea, and the Indian Ocean, that he observes the differences in the spectrum which he has spoken of in the article just referred to; he informs us that his later observations lead him to believe that the changes in the atmospheric humidity distinctly correspond to changes in the solar spectrum; that, for instance, an increasing humidity manifests itself by a shortening in of the blue, and by a well marked development of aqueous bands in the red and yellow. Whether further examination will confirm this belief or not it is at present impossible to say, but the spectroscope has done so much towards teaching us the constitution of other atmospheres, that we may fairly entertain a hope that the time has come for it to teach us something about the distant and outlying parts of our own. J. K. L. Index of Spectra. By W. M. Watts, D.Sc. (London: Henry Gillman.)

ALL workers with the spectroscope must have felt the great inconvenience arising from the employment of numberless different scales in the mapping of spectra. It is to be hoped that at some future time there will be more uniformity, and that authors, when publishing original memoirs, will reduce their measurements to a definite and recognised system. It is clear that such a method must be perfectly independent of the spectroscope and its concomitant parts; the position of each line can therefore only be expressed by its colour, or, in other words, by the length of the wave of light which produces this colour. Dispersion spectra, obtained by the use of prisms of different materials, vary greatly in the relative breadth of the respective colours; thus in the spectrum from crownglass the red end is larger and the blue end shorter than in the spectra obtained from flint-glass, carbonic disulphide, and by diffraction. It is therefore necessary in spectroscopic researches to record the positions of numerous well-known lines as observed in the instrument that is used. In a diffraction spectrum, however, the position of the lines is dependent solely on their colour, and is precisely the same by whatever method the spectrum is obtained. For the results of different observers to be accurately comparable, the readings obtained by dispersion must either be expressed in wave-lengths, or the spectra must be obtained by diffraction. The wave-lengths of the Fraunhofer lines of the sun have been accurately determined by several observers. The author has adopted as the basis of his work the measurements made by Angström, as these appear to exceed in accuracy all similar measurements at our disposal. When the wavelengths of a number of lines are known, it is easy to calculate the wave-lengths of the lines of any new spectrum, either by the interpolation formula given by W. Gibbs Phil. Mag. [4] xl.157) or by the method of graphical inter

polation, both of which methods are explained in the volume before us; all that is required is to have the wavelengths of two known lines, between which the line to be measured falls. By the aid of Angström's measurements the author has reduced the measurements of the bright lines of all the elements whose spectra have been carefully investigated, and also of air lines as mapped by Thaler, Huggins, and Plucker. These tables will therefore assist materially in the work of reduction, by serving as landmarks from which to calculate the wave-lengths of new lines. The attention that the author has bestowed on this work is the best guarantee of the accuracy of the numbers given. In the lithographic plates at the end of the tables, a drawing of the spectrum of each element is given on the plan proposed by Bunsen, in which the intensity of a bright line is indicated by the height of the line representing it; a chromo-lithograph is given of the double spectra of nitrogen, sulphur, and carbon, and another plate, showing two spectra obtained by Wülner from aluminium, and three from hydrogen at different powers. Dr. Watts is deserving of the best thanks of all those interested in spectroscopic work, for it is to be hoped that his "Index of Spectra" may contribute to the adoption of a uniform scale of measurement, and thus facilitate the advance of the science. A. P.

LETTERS TO THE EDITOR

[The Editor does not hold himself responsible for opinions expressed by his correspondents. No notice is taken of anonymous communications.]

The Adamites

PHILOLOGISTS will notice with regret a paper bearing the above title in the late number of the Journal of the Anthropological Institute. The author appears to have taken up, without proper study, that difficult and dangerous line of argument, the comparison of historical names, and has naturally fallen into the network of delusive fancy which in past generations entangled Jacob Bryant and Godfrey Higgins. Modern philology has abundantly proved that slight, loose, and occasional correspondences in proper names are deceptive as evidence, even among languages of the same family, much more among languages of different families. It is a fair sample of the present paper, that it argues an affinity between the peoples of the Old and New Worlds on the basis of a connection between various names of the Deity, among which are the Russian Bog, the Mantchoo Ab-ka, and the Hottentot Teqoa. The special purpose is to prove that nations are shown by their names to trace descent from an ancestor called Ad-" Adam, or Father Ad." Thus "the great Hamitic race of Akkad" is interpreted by the aid of Welsh ach-root, lineage," so as to mean sons or lineage of Ad;" and the name of Ta-ata, the Polynesian First Man, is "that of the mythical ancestor of the Adamites, reversed, however, and with the addition of ata (aka), spirit"! It is obvious, though unaccountably overlooked in the paper, that two of the clearest cases of the theory may be found near home. The descent of two nations from Father Ad is perfectly recorded by ourselves, when we call the representative of one a Paddy, clearly Ap-Ad (from Ap," used in the sense of son"), while the other's Adamite ancestor is commemorated by calling his descendant a Ta-ffy.

It is not necessary to give the name of the author of this unlucky paper. Everybody is liable to slips, great or small; and a man may have done work worth doing in one line, but turning suddenly to another, may come to grief utterly. But the Council of the Anthropological Institute should have consulted their own interest and that of their contributor by declining to print the present essay. It is the duty of a learned society to examine its members, but not to put it on public record against themeven a hasty and ill-considered idea brought forward by one of selves and him.

The Segmentation of Annulosa

M. A. I.

IN the extract from his Address to the Entomological Society, given in NATURE, February 29, Mr. Wallace remarks that Mr. Spencer's views have not been so much as once alluded to in the

discussion of the Origin of Insects. The general question of the Annulosa obviously includes that of Insects, and I therefore desire to correct this statement, and to refer your readers to a paper by me on Chœtogaster and Æolosoma, published in the "Linnean Transactions," vol. xxvi. (read Dec. 1867), in which I have more than alluded to Mr. Spencer's views, and have offered some suggestions on the morphology of the head, and as to the unisegmental Annulose ancestor. Mr. Wallace quotes from this paper in reference to Chatogaster, though from the context it would appear that he is quoting from Professor Owen. Since the researches which have rendered Mr. Wallace's name one of the first among living zoologists have not led him into practical anatomical and embryological studies, I may venture to add one or two strictures upon his statements relating to such matters. In the first place, those who are engaged in the study of insect embryology are not ignorant of Mr. Spencer's or similar views; the wide-spread study of his works in England and America, and of Haeckel's general morphology in Germany, is sufficient guarantee of this. But even if it were as Mr. Wallace supposes, he has not, in the extract given in NATURE, shown at all how Mr. Spencer's views on aggregation are to influence the study of the embryology of insects. Of course, the general theory of somites has immense importance in all studies relating to the Annulosa, but in what way the particular form of it, due to Mr. Spencer, can influence conclusions drawn from the observation of the manner in which insects develop from the egg, Mr. Wallace does not explain. Whether, admitting or denying the truth of Mr. Spencer's or Prof. Haeckel's views, it would be equally conceivable, did the observed facts point in either direction-that the ancestry of insects is to be traced to a simple nauplius-form or to a multi-segmental Annelid-like progenitor, the question of segmentation is not finally settled, though it is largely elucidated by the doctrine of Mr. Spencer. It is no doubt an instructive point of view to take-that segmentation is an arrested production of zooids, but it is equally true that the production of zooids is an exaggerated segmentation. We have no grounds for assuming the one more than the other as the essential process; they are both phases of the same process. The fact appears to be that in certain masses of organised matter, on their reaching a certain limit of growth, "polarities," which were hitherto held in one system, break up into two and so on. The simplest case of this is cell-division, but whether the systems separate entirely, as in simple fission, or remain associated, as in the cleavage of the egg and in the seg mentation of the Annulosa, depends on another factor, a cohesive or integrating force proper to the growing mass.

In the present state of knowledge upon the subject, the assumption adopted and held of so much importance by Mr. Wallacethat the Vertebrata do not exhibit a segmentation of the same kind as that of the Annulosa, is by no means justified. Though much of their jointed iterative structure may probably be due to that kind of adaptation which Mr. Spencer so justly distinguishes as "superinduced segmentation," yet that there is a fundamental bud-segmentation, or segmentation of growth identical with that of Annulosa, is in the very highest degree probable. And even as to the Chiton, which Mr. Wallace quotes from Mr. Spencer as quite certainly an example of superinduced segmentation, I think that had he examined the grounds for making such a statement, he would have hesitated. The larva of Chiton is identical with that of an Annelid, and its segmentation makes its appearance in the same way. Why should there not be segmented molluscs? It is necessary most constantly to bear in mind, when considering this matter of segmentation, the possibility of the partial or complete obliteration of segmental characters due to tertiary aggregation, and their modification in most various ways in the evolution either of an individual or of a group.

Further, as to Mr. Wallace's expressions with regard to the segmentation of insects. From what was said above as to the relation of segmentation and zooid production, it follows that the conception of segmentation is erroneous which leads to ascribing to insects peculiar physiological or psychical properties on account of their being composed of "a number of individualities fused into one." This expression should not be allowed to lead to wider conclusions than those it formulates. As a matter of fact, insects are not a number of individualities fused into one, but rather one individuality partially (and as a reminiscence rather than actually) broken up into many, this partial breaking up being due to the mechanical properties of its tissues at a certain period of development,

If, by the "spiracles" of Annelids, Mr. Wallace means the segmental organs, it should be clearly stated that the identity of these with the trachea of insects has not yet been in any way proved. The comparison of the mode of development of these two sets of organs is just one of the points upon which embryologists are now at work.

Lastly, the researches of the last fifteen years do not, I venture to submit, lead to the conclusion adopted by Mr. Wallace, that the parthenogenesis of the higher Annulosa is analogous to or identical with gemmation as opposed to sexual reproduction or digenesis, but to the conclusion which is exactly opposed to this, namely, that it is identical with digenesis in all particulars but the absence of the male element. Naples E. RAY LANKESTER

Adaptive Coloration, Phosphorescence, &c.

No one who has watched a very young hare stealing from a green covert to brown soil, and observed its cunning movements there when alarmed, can for a moment doubt the value of colour as a protection to the higher animals.

The remarks by Mr. E. S. Morse in NATURE of last week bring to my recollection a good instance (among invertebrates) which occurs on the reddish granite of Cobo Bay, Guernsey. There Trochus lineatus especially abounds on the bare parts of the rocks between tide-marks; and every observer must be at once struck by the remarkable fitness of the mollusk for its peculiar site.

Mr. Darwin in truth says," "It would not, for instance, occur to any one that the perfect transparency of the Medusæ or jellyfishes, was of the highest service to them as a protection; but when we are reminded by Häckel that not only the Medusa, but many floating mollusca, crustaceans, and even small oceanic doubt that they thus escape the notice of pelagic birds and other fishes, partake of this same glass-like structure, we can hardly enemies;" but he makes no mention of the gorgeous colouring of some of these swimming jellies, nor is there any allusion to their remarkable property of phosphorescence. The transparency sea-birds, which hover in multitudes over them, masses of of the British Salpæ does not prevent their being attacked by Medusa and other Hydrozoa, and a few minute fishes.

If instead of promulgating the visionary idea that the abysses of the ocean depended for their light on phosphorescent animals, the dredgers+ in the Porcupine had applied the notion that the various luminous marine animals used their light to attract each other, so that the most luminous might have a better chance of continuing the race, they would have been able to say more in its favour, without, at least, running counter to established facts. Murthly, March 26 W. C. MCINTOSH

The Aurora of February 4+

AN aurora of a very unusual splendour for the latitude was seen here on Sunday evening February 4, 1872. The sky, extending in azimuth over 197° from N. E. to nearly W.S. W., was generally illuminated. The brilliance of the glow varied considerably in different directions from time to time during the night. On the south horizon there was a bright bluish segment of light, whose position in azimuth and brilliance varied slightly from time to time. The streamers were well seen, and their convergence towards the point to which the south pole of a magnet is directed could be most distinctly traced. The streamers extended at about nine o'clock to the constellation Orion, and Sirius was well within the auroral glow. With a spectroscope I saw one bright line in the spectrum of the auroral light, but the spectrum was too faint to allow of any successful attempt to determine the refrangibility of the light. Unfortunately our magnetical equipment is such that I can give no information respecting the extent of the magnetical disturbance at the time. The aurora was seen as far north as Bloemfontein, latitude 29° 8' south. A faint aurora was seen here in October 1870, but no such aurora as that of February 4, 1872, appears to have been visible for at least fifty years. The aurora was well seen over a large portion of the colony, and considerably frightened the natives. E. J. STONE

Royal Observatory, Cape of Good Hope, Feb. 19

* "Descent of Man," vol. i., p. 322.

+ Not, however, Mr. Jeffreys

Communicated by the Astronomer Royal.

SEEING your account of the aurora of February 4 in NATURE of the 22nd, reminds me that on the evening of the 4th I was riding from Cambridge to Coldwell, in Ohio, and between six and seven o'clock saw a most brilliant display of auroral light in the southern quarter of the sky. Brilliant streamers shot up past the zenith, while the whole southern portion of the sky was brightly illuminated with a corruscating rose-coloured light. Marietta, Ohio., March 15 A. J. WARNER

Morse on Terebratulina

I HAVE just read the very kind notice of my paper* in the pages of your journal from the pen of Mr. E. R. Lankester. I hasten, however, to remove one impression conveyed in the following sentence, respecting the opinions I hold as to the Annelidan affinities of the Brachiopods:

"We are not sure whether Mr. Morse adheres to this startling proposition."

I trust the long delay in publishing the results of my studies on this interesting class will lead no one to suppose that I have yet seen reason to modify the position I took two years ago regarding their position in the animal kingdom. On the contrary, continued investigation has brought out many new points of interest, and now I hope, ere my paper is published, to present the embryology of some one of them.

I had studied our native Terebratulina, its structure, as well as its early stages, and through the kindness of Prof. Verrill, had studied Discina lævis (upon which I hope soon to publish).

Mr. Lankester, as the author of many valuable memoirs requiring much skill and patient labour, will fully appreciate the time and care necessary in work of this kind.

at all.

As to my being unduly impressed at the sight of living Lingule, I may say, in justice to myself, and my friends will testify to it, my opinions were fully formed before I ever saw Lingula With the caution that is requisite for every one, if he does not wish to supplement his paper with a correction of errors, a way of doing things altogether too frequent in this country, I deemed it important to study living Lingula before publishing. It was impossible for me to go half-way round the world for it. And as three specimens of another species have been found on the coast of North Carolina, I determined to go there. A trip of nearly a thousand miles brought me to its waste of drifting sands.

Thoroughly convinced as to the correctness of my views, and these views of sufficient strength to convince my co-labourers, Mr. Lankester will understand my enthusiasm when, after a week's fruitless search under a blazing sun, and an almost hopeless task, I found Lingula, not as we have always supposed attached by its peduncle, but living in the sand, precisely like many tubicolous worms, building a true sand tube, and when liberated from it crawling and burrowing by means of its setæ, and with all these welcome characters it should greet me with red blood. Not that I lay great stress on any one of these characters, but having made my deductions from the most common form, Terebratulina, one can readily understand the bearing of such unexpected characters in this little Lingula.

Mr. Lankester will admit that the Vermian lumber room has some orderly compartments; into one of those I place the Brachiopods far away from all Molluscan odours.

The distinguished naturalist, Prof. Steenstrup, informs me that he has long taught his classes at the University of Copenhagen that the Brachiopods were true Annelids, and that my views are thoroughly endorsed by him. To him, therefore, and not to me as had been supposed, belongs the priority of this discovery.

I only ask a little patience till my complete paper is published on the Brachiopods as a division of Annelida, in which I shall give appropriate figures, and my reasons in full for the position I have taken. EDWARD S. MORSE

Salem, Mass., U.S.A., March 14

On the Colour of a Hydrogen Flame WHEN hydrogen and oxygen are burned together, it is well known that the flame produced is almost non-luminous; it always, however, exhibits an unmistakeably blue tinge.

The small illuminative power is generally referred to the "absence of solid particles." This view, it appears to me, draws a too rigid line of demarcation between the atoms of carbon in an ordinary gas-coal flame and the atoms of hydrogen in that of *"Early Stages of Terebratulina."

the oxyhydrogen. The cause of the phenomenon does not depend so much on the solidity as it does on the time of oscillation of the particles which constitute the flame. Water particles in all their states of aggregation preserve the same time of oscillation-extra red; hence a hydrogen flame should be perfectly invisible whatever may be the " solidity" or density of its particles.

But the flame is not invisible, and, what is still more remarkable, the colour which it does exhibit is found to belong to the most refrangible end of the spectrum. To explain this strange phenomenon, it appears to me that it is necessary to invoke a state in the ether particles similar to that which Helmholtz has shown to exist in air; and which is this :-A tuning-fork "vigorously struck against a pad emits the octave of its fundamental note. Now, the first overtone of a tuning fork is produced by vibrations about 61 times as rapid as the fundamental; duced solely in consequence of the fact that the initial disturthe octave, therefore, is not an overtone of the fork-it is probance is great in proportion to the distance of the air particles from one another, secondary waves being produced whose periods are twice as rapid as those of the fundamental.

The amplitude of the particles in a hydrogen flame is known to be very great, and hence it seems probable that an effect may result from the disturbance thus created in the e her, analogous to that in the case of air, i.e., associated with the fundamental vibrations of the hydrogen flame we have their octave, which would obviously be within the visual range, and correspond very closely, if not exactly, with the colour actually observed.

Should this surmise prove correct we have plainly an easy means by which we can determine the wave-length of those extra-red rays which are absorbed by water. A. G. MEEZE

Hartley Institution, Southampton, March 26 P.S. May not the great actinic power of the electric light be due in a great measure to the secondary waves produced by the magnitude of the disturbing force?

VESTIGES OF THE GLACIAL PERIOD IN NORTH-EASTERN ANATOLIA

ATTENTION was drawn to this subject in a lecture given on March 25 at the Royal Geographical Society by the Eastern traveller Mr. W. Gifford Palgrave, at present British Consul for the northern coast of Asia Minor. The facts which he mentioned had been principally observed by him during a tour on duty to the interior about two years ago; and the line of route lay from the town of Trebizond on the sea coast to that of Erzinghian on the Upper Euphrates.

The phenomena themselves were divided into two classes: the one referable to the highlands which he had then traversed, the other to their marginal region.

These highlands are situated on or near the 40th parallel of latitude, and extend between the 37th and 44th of longitude, east and west; their average breadth being about fifty miles, and their elevation varying from 3,000 to 9,000 feet above the sea. They constitute the great watershed of Eastern Anatolia ; the rivers to the south of them flowing into the Persian Gulf, and those to the north into the Black Sea. To the west is the basin of the Halys, to the east that of the Caspian.

The road leading across this plateau towards Erzinghian, mounts up to it by a defile named "Ketcheh-Dereh,” or "Goats' Valley." Here, at a height of about 5,400 feet above the sea, Mr. Palgrave came on the lower extremity of a large moraine, piled up to a height of more than twenty feet, and broad in proportion. Following it for a distance of nearly half a mile, he found that when it had reached between 400 and 500 feet higher up the slope, it forked into two lesser branches, continued each a good way further into the rising undulations of the table-land.

The plateau itself bore every mark of having lain under a thick ice-coating; its eminences and irregularities all bearing the "moutonnée" character impressed by glacia. action; while it was also frequently strewn with detached