July 2 1, 1887] 



NATURE 



269 



the conditions of life." Was not this a prophet ? Yea, I say unto 

 you and more than a prophet ! Of course if the conditions of 

 life are unfavourable, the incipient variations cannot become 

 species. But surely it is obvious that in variation is the real 

 orii^in of species. Variations must occur before the selection of 

 some of them in preference to others. To consider the theory of 

 natural selection as a theory of the origin of species, is therefore 

 clearly an error. In his " Origin of Species" Darwin certainly 

 expounded variation, and I might have ventured to think that as 

 the book deals more largely with the subsequent selection of a 

 few varieties to survive as species at the expense of many 

 extinguished, a more exact title for it would have been "The 

 Evolution of Species. " liut what says the great master ? See 

 page 71 : — "Owing to this struggle for life, any Turi'ilion, how- 

 ever slight . . . vj'iW \.tn(\.io \.he preservation oi that individual, 

 and will generally be inherited by its offspring. ... I have 

 called this principle by which each slight variation, if useful, is 

 preserved, by the term natural selection, in order to mark its 

 relation to man's power of selection." And who will not re- 

 cognize the wisdom of his selection of the term ? It has been 

 before observed that the "Ascent of Man " would seem a more 

 accurate title than the '^Descent of Man." But I have no 

 doubt that his reasons for preferring the latter were equally 

 cogent. 



But Mr. Romanes proceeds: — "This proof is drawn from 

 three distinct heads of evidence, (i) The inutility to species of a 

 large proportional number of their specific characters. (2) The 

 general flict of sterility between allied species, which admittedly 

 cannot be explained by natural selection, and therefore has 

 hitherto never been explained. (3) The swamping influence of 

 even useful variations of free intercrossing with the parent form." 

 I have advanced, I think, ample reasons why No. 3 may be 

 regarded as imaginary, and which therefore reduce the value of 

 No. 2 to a minimum. No. I depends entirely upon the defini- 

 tion of ";///7«Vj'." Has t'.is word any real significance outside 

 human interests and considerations ? The idea of utility, if 

 extended to Nature's operations, may, it seems to me, apply to 

 the interests of any other variation than the one whose specific 

 characters are in question, which may therefore be, without com- 

 punction or regret, sacrificed to the most fit, as we know that 

 innumerable species have been extinguished in the interest of 

 those that su[)planted them. But utility to Nature may be the 

 extinction of one variation and the preservation of another. As 

 Mr. Romanes's whole paper is built upon what I have already 

 quoted from it, I need scarcely follow it any further. With your 

 permission, however, I have another remark to make. 



Mr. Romanes seems to me to have been much exercised by 

 the consideration of the intercrossing with parent forms, and, not 

 knowing of the simple solution given above, to have cleverly in- 

 vented his physiological selection to escape from the dilemma. Of 

 course Nature is not clever, but simple in its operations. I was 

 always much impressed with what appeared to me a greater 

 difficulty, which might be thought to have a clearer title to be 

 called " physiological selection." I allude to a general tendency 

 in the (human at least) sexes to prefer a mate with opposite 

 characteristics, with the apparent result of insuring mediocrity in 

 the progeny. Thus, as a general rule, the tall prefer the short ; 

 the dark, the fair ; the wise, the silly ; &c., and vice versd. 

 Variation is, on the other hand, apparently insured to a large 

 extent by the differences between parents, but still it would seem 

 that the tendency should, cateris paribus, be inevitably towards a 

 mean in the progeny. The general migration, however, as above 

 indicated, of young males and females, gives plainly ample 

 opportunity for the preservation of viable variations, besides 

 others which experience and care will doubtless discover. 



Melbourne, April ll. H. K. Rusden. 



Weight, Mass, and Force. 



Applications of the data previously given, in the extract 

 from the American journal, to the dynamical principles of 

 varied motion are easily provided for Mr. Hay ward. Take the 

 following : " Determine the weight of the greatest train the 

 Strong locomotive can take up a 96-feet grade from rest at 

 one station to stop at the next station a mile off in four minutes, 

 taking the brake power as a resistance of 400 lbs. to a ton." 



The main points at issue, however, are whether the language 

 of the engineer, and in fact the usage of our own and other 

 languages, is scientifically correct or incorrect in its use of the 



words 7veight and weighing ; and whether the mathematician 

 is to be allowed to restrict the word weight to the subsidiary 

 sense of force of attraction by the earth. 



It is of great importance that this question of dynamical 

 terminology should be thoroughly thrashed out now, before Mr. 

 Hayward's Committee on Dynamics, of the Association for the 

 Improvement of Geometrical Teaching, prepare their final 

 report on the subject. A. G. Greenhill. 



Woolwich, July 11. 



The Sky-coloured Clouds. 



On the evenings of June 14, 18, and 19 there was a feeble re- 

 appearance in Sark of the sky-coloured clouds, as I may call them 

 in default of abetter name, which were so brilliant in the twilights 

 of the last two summers. Though the display this month has 

 been comparatively faint, it has been unmistakably of the same 

 character. I have seen nothing of these clouds since the 19th 

 in travelling in the Channel Islands and through France. 



Geneva, June 29. T. W. Backhouse. 



P.S. — Cha7nounix,July 13. — I have seen one more display — a 

 brilliant one seen from this neighbourhood on the 6th inst. — 

 T. W. B. 



The Migrations of Pre-Glacial Man. 



The question raised by " Glaciator " has been treated by me 

 in a paper entitled "The Faunas of the Ffynnon Beuno Caves 

 and of the Norfolk Forest Bed " in the Geological Magazine for 

 March 1887. I there stated that, "Although man probably 

 reached this country from the east, it seems to me equally clear 

 that he must also have arrived here with the reindeer from some 

 northern source during the advance of glacial conditions." 

 Though the Norfolk Forest Bed fauna contains abundaiit 

 remains of deer and of other animals suitable as food for man, it is 

 curious that so far no implements or other traces of man have 

 been found there. The Forest Bed contains in the main the 

 fauna of an eastern area, as the river on the banks of which the 

 animals roamed flowed from the south-east. If pre-glacial man 

 arrived in this country from the east or south, we should therefore 

 expect to find evidences of this in the Forest Bed. On the other 

 hand, wherever the remains of northern animals, such as the 

 reindeer, mammoth, and rhinoceros, occur in any abundance, 

 there we almost invariably find traces of man. Now that we 

 know that man arrived in this country before the climax of the 

 Ice age, as proved by the explorations carried on for several years 

 at the Ffynnon Beuno Caves (amply confirmed also by this year's 

 researches), it seems but natural to infer that man arrived in this 

 country with the northern animals as they were compelled to 

 migrate southwards by the gradually advancing glacial conditions, 

 and that he kept mainly with the reindeer near the edge of the 

 advancing ice. Henry Hicks. 



ABSTRACT OF THE RESULTS OF THE IN- 

 VESTIGATION OF THE CHARLESTON 

 EARTHQUAKE} 



I. 



THE amount of information now in possession ot the 

 United States Geological Survey, relating to the 

 Charleston earthquake, is probably larger than any of 

 similar nature ever before collected relating to any one 

 earthquake. The number of localities reported exceeds 

 1600. The sources of information are as follow : (i) we 

 are deeply indebted to the U.S. Signal Service for fur- 

 nishing us the reports of their observers ; and (2) equally 

 so to the Lighthouse Board, which has obtained and 

 forwarded to us the reports of keepers of all lighthouses 

 from Massachusetts to Louisiana, and upon the great 

 lakes ; (3) to the Western Union Telegraph Company, 

 which instructed its Division superintendents to collate and 

 transmit many valuable reports ; (4) to the associated 

 Press, which has given us access to the full despatches 

 (with transcripts thereof) which were sent over the wires 



' Paper re.id before the National Academy of Sciences at Washington, on 

 April ij, 1887, by C.E. Button, U.S.A., and Everett Hayden, U.S.N.,U.S. 

 Geological Survey. 



