Oct. 3, 1872] 



NATURE 



455 



an explanation in some measure correct, clear skies are not so 

 unknown in Europe and America (nor indeed in England) that 

 the illumination of the atmosphere can be broadly said to " com- 

 pletely overpower " that which " in an ordinary instinment " is 

 by no means overpowered in India in ordinary stales of the sky. 



The erroneous notion to which I refer has been promulgated 

 again and again. It is unnecessary that I should specify the 

 various passages — in lectures and elsewhere — and ultimately in 

 Mr. Proctor's work on the Sun* : but having now found it so 

 distinctly enunciated in the above cited passage, and elsewhere, 

 in " Schellen," the time seemed to have come when it ought no 

 longer to pass unnoticed ; the more so as I have never been able 

 to understand the real reason why the momentous discovery was 

 not made earlier. It has been said that titoiciiig Tv/icir fa look, 

 the main difficulty was overcome. But two days after my first 

 experience of these three known lines. I recognised tlie presence of 

 three more hitherto unknown ones — and subsequently of a seventh. 

 From that time to this however I have not seen any others, with 

 the same dispersive power. 



If asked how it was that, with the very same power at command, 

 I had not myself seen them before ; I need only reply that I had 

 small leisure by day, and was under the impression that the ex- 

 periment had been fruitless in more experienced hands — the 

 identical reason which P. Secchi has given for a like remiss- 

 ness, in this very matter. 



Bangalore, Aug. 25 J. Herschel 



Botanical Terminology 



I VENTURE, as no one else has done so, to make a few remarks 

 on Mr. Kitchener's letter. 



I suppose the necessity will not be denied of employing some 

 technical terms in studying su'^jects which do not fall under 

 ordinary observation, and for the discussion of which ordinary 

 language is consequently insufficient. When these technical 

 terms are first devised, it is natural, indeed unavoidable, that 

 they should reflect the scientific ideas current at the time. 

 But inasmuch as knowledge progresses, we find ourselves, 

 sotmer or later in every brancli of science, in the predicament of 

 having to give elTect to new views in terms which are an inheritance 

 from old ones. We are able to do this because things themselves 

 remain the same though our ideas about them change, and the names 

 they once received with an intelligible meaning have now be- 

 come purely arbitrary. No man bearing the name of, say, 

 Baker, would probably change his name because he did not 

 make bread. Nor do chemists discard the term oxygen because 

 there are acids of which it is not a constituent. In the same way 

 the morphological analogy implied in the use of the term 

 "ovule," in the case of plants, is undoubtedly incorrect, but 

 any one must have a singularly tender conscience who would 

 object to it on that ground. 



To save, therefore, confusion, and preserve uniformity in 

 scientific literature, there is a tacit convention to treat in a great 

 many cases as arbitrary terms words which once im]iUed ac- 

 quiescence in a theory. That a word in common use belongs to 

 ' a pre-Adamite stage of botanical knowledge," as Mr. Kitchener 

 calls it, is not, I take it, sufficient ground for replacing it with 

 another if there is no ambiguity in its application. 



Next I would remark that Mr. Kitchener appears to me to 

 have an exaggerated notion of the copiousness of botanical 

 terminology. The number of terms really indispensable is not 

 large. For example, he speaks of the troop of words ending in 

 " tropous. " Was this particular noun of multitude suggested by 

 the termination ? because as a matter of fact the troop consists of 

 three. Prof. Ilenslow found no difficulty in teaching the terms 

 contained in Prof. Oliver's Lessons in Elementary Botany to 

 girls in a village school. Surely the Rugby boys cannot be less 

 apt. 



That Professor Henslow succeeded seems to dispose of the 

 objection that a knowledge of (jreek is "a necessary open 

 sesame to the correct remembering and spelling of botanical 

 terms." To teach these terms as " unintelligible gibberish " is 

 only what in any case must be done with whole hosts of words 

 not very different in form. Why should it be insuperably diffi- 

 cult for a boy, even if ignorant of Greek, to remember spell and 

 apply the term hypogonous when he cannot possibly evade some- 

 time or other having to face hypothesis, hypochondria, and 

 hypocrisy, to say nothing of hydrostatics, hydr.aulics, hydrogen, 

 and hydrocephalus ? 



' Sec particularly p. 200, footnote. 



I can see no reason why, as Prof Henslow was in the habit ot 

 doing, technical terms carefully reduced to the smallest number 

 absolutely required (and text-books bristle witli unnecessary ones) 

 should not be taught to boys as mere arbitrary names. Synge- 

 nesious, as a mere matter of taste, seems to me preferable to . 

 "united by dust-pouches." 



If this be done, Mr. Kitchener's further difficulty as to " gamo- 

 genetic analogy " disappears. 



The teacher, of course, may himself reasonably exercise some 

 liberty. Thus no one would, I suppose, object to quincuncial 

 being expressed by |, though 'quincunx is to be found in any 

 dictionary, and is a word for which botanists are not responsible. 

 Again, the suggestion to express by a fraction the depth of leaf- 

 incision is really commendable, even to techaical descriptive 

 botanists. 



October.! W. T. Tihselto.v Dyer 



The Hassler Expedition 



Under this heading in your number for August 29, p. 354, is 

 this sentence, "One lesson I must confess to having learned at 

 Indefatigable Island (Galapagos). I saw there indisputable 

 proof that the surf of the seals capable of rounding angular frag- 

 ments of lava into pebbles somewhat resembling in shape (but 

 not at all in polish and grooving) glacial boulders. I had always 

 from boyhood doubted the power of the sea to make angular 

 fragments round. I had supposed that the action of the surf 

 upon such fragments would be simply to pack them into a sort of 

 RIcAdam's roadway. And even now, having had the proof that 

 under peculiar circumstances the sea can make a tolerable imita- 

 tion of drift, I am not a whit more ready to believe that the sea 

 made the drift itself You may prove to me experimentally that 

 flour can be made from wheat with a pestle and mortar, but thai 

 will not convince me that the flour markets of the world are thus 

 supplied. " 



If the countless myriads of tons of beach c5n the shores of this 

 globe could be passed through the hands of this writer, he would 

 not detect a single "angular fragment" (McAdamised) among 

 them. On the shore each lump of rock is successively worn into 

 a boulder, each boulder into a pebble, and finally each pebble 

 into sand. This is the main source of the sand which lies 

 between the beach and the ooze-bed of the ocean. 



But the sea-shore factory of boulders and drift is not the only 

 factory, or even the largest factory of boulders and drift. The 

 rocky gullet is the main boulder factory. Lyell (Principles), 

 speaking of Etna, attributes " the enormous rounded boulders of 

 felspar, porphyry, and basalt, a line of which can be traced from 

 the sea from near Giardiiii, by Mascali and Zapharana to the 

 Val del Bove " to one flood of melted sno\\'. The valleys of the 

 low part of Teneriffe, away from the Pe.ak and near Santa 

 Cruz, are almost all dry except in rain. The beds of the 

 upper parts of tliese valleys are sheer rock, the middle parts 

 wear the appearance of torrents of boulders, the lower parts are 

 alluvial plains of boulders, and opposite the mouths of these 

 valleys are very commonly deltas and bars of boulders. Behind 

 these bars, after each rain, large deposits of earth and sand are 

 formed which the people collect diligently. Where permanent 

 streams exist, they are usually lost at a considerable distance above 

 the mouths of the valleys. That is, except in rains, they perco- 

 late to the sea beneath the plains deltas and bars of boulders. 



From the sides, hundreds or thousands of torrents of boulders 

 fall into these rivers of boulders. Sometimes these lateral shoots 

 have formed barriers of boalders across the main valley behind 

 which large beds of boulders and earth have accumulated, again 

 to be cleared out and thrust down to the sea-shore by heavy 

 longitudinal rain floods. 



So, in Madeira, who does not know the sea-shore boulders of 

 the Praya- Formosa? and for fresh water boulders, the stream at 

 Funchal brings down sucli a crop at every flood as to choke the 

 channel through its delta of boulders, and unless the channel is 

 kept clear of them artificially, the lower town is subject to the 

 most disastrous inundations. 



I mention Teneriffe and Madeira because, like the Galapagos, 

 they are deep-sea volcanic islands. Their surfaces have been 

 ejected when they were already above the sea, and they have been 

 coated and re-coated thousands of times by floods of melted rock 

 when they had long lieen sub dio. So that I conclude that even 

 Agassiz would not attribute the moulding of their surface to the 

 " Glacial epoch." But leave volcanic islands or volcanic moun- 

 tains out of the question, there is not a mountain stream or 



