474 



NATURE 



[February 9, 191 1 



iho magnetic equator and describing a circular orbit con- 

 centric with the earth. The magnetic force due to the 

 earth's magnetic field is directed towards the north, and 

 the deflecting force must be directed towards the centre to 

 keep the corpuscle in its orbit. Applying the well-known 

 rule for electromagnetic deflection, we find that the 

 corpuscle, if negative, must move from west to casi. 



The question regarding the simultaneity of the occur- 

 rence of the positive equatorial storms is a very important 

 one for their physical explanation, for if it takes a time 

 of several minutes for the pulse to travel round the earth, 

 we must suppose that the currents producing the effects 

 are near the earth compared with its diameter, while 

 simultaneity of beginning would indicate very distant 

 systems. The question of simultaneity can only have a 

 definite meaning in the case of the abruptly beginning 

 storms, e.g. the positive equatorial storms {" S " storms), 

 and perhaps the cyclo-median storms. The polar storms, 

 on the other hand, usually set in gradually, and near the 

 auroral zone, where they are strongest, they are of a very 

 local character ; sudden changes at one station may have 

 no corresponding sudden change at another ; but in the 

 case of these polar storms (cf. Birkeland's work) it is 

 often found that the centres of disturbance fields move 

 slowly, usually along the auroral zone. 



It has usually been assumed that the positive equatorial 

 storms set in simultaneously all round the world. The 

 question is very carefully examined in the work of Birke- 

 land, referred to above, for the storm of January 26, 

 1003. Looking at his figures, we notice that correspond- 

 ing serrations show small differences in time at different 

 stations, amounting to two or three minutes ; but these 

 differences are equally great for neighbouring stations as 

 for more distant ones. The differences for neighbouring 

 stations, which must be due to some error, are not so 

 much caused by faults in the measurements on the time 

 axis and the identification of corresponding points on the 

 curves ; they are rather to be considered as faults sticking 

 to the magnetogram itself, for if we take out the time of 

 several points of the disturbance, the time differences for 

 corresponding points for two stations come out nearly 

 constant. 



Dr. R. L. Paris and Dr. Bauer, who have made a 

 great amount of valuable work on the subject, have tried 

 to eliminate the error by collecting neighbouring stations 

 into groups, and then taking the difference between the 

 average time of each group, and they arrive at the con- 

 clusion that the occurrence is not simultaneous. But so 

 long as the differences between the groups are of the 

 same order as the actual possible error of determination, it 

 seems very dangerous to conclude to a non-simultaneity. 

 Moreover, Mr. Krogness, by comparing the times of 

 beginning of a number of storms at Potsdam with the 

 corresponding times given by Dr. Paris for a group of 

 stations on the western hemisphere, has found almost 

 perfect simultaneity. 



I think, then, that the present position of the question 

 cannot be expressed in a better way than by the follow- 

 ing statement taken from Prof. Birkeland's work : — 



" We may conclude from this that the serrations appear 

 simultaneously, or rather, the differences in time is less 

 than the amount that can be detected by these register- 

 ings. " L. Veg.ard. 



University of Christiania, January 14. 



Sir F. Galton and Composite Photography. 



May I be permitted, as an intimate friend of many 

 years and under deep obligations to the late Sir Francis 

 Galton, to say a word upon a matter which is perhaps not 

 sufficiently emphasised ? I refer to his very deep and last- 

 ing interest in composite photography, and his conviction 

 of its scientific value. He considered it capable of and 

 well worth systematic development. This was a frequent 

 subject of conversation between us ; and he told me many 

 times (sometimes with reference to the original contribu- 

 tions to photography of my brother, Colonel Stuart- 

 Wortley) that he felt the method ought to be developed, 

 not as a newspaper curiosity, but as a serious aid to 

 sociology, and especially to the studv of heredity. 



Prof. Bowditch, of Harvard, told me that he found 



NO. 2154, VOL. 85] 



an unaccountable indifference on the subject in America, 

 while he entirely shared Galton 's view of its possibilities. 



If anyone could be found to take up the matter seriously 

 there can be no doubt that the pioneer would be richly 

 rewarded. In our last talk, a few weeks before his death, 

 Sir Francis himself told me of really sensational results 

 from the few experiments he was able to make with a 

 comparatively primitive instrument. For instance, he told 

 me he had collected photographs of Queen Victoria and 

 Prince Albert and all their children. To his great sur- 

 prise, the composite gave the likeness of Princess Alice 

 and no one else. But this was only one of many equally 

 suggestive results. Victoria Welby. 



Duneaves, Harrow, February 3. 



Darwin and the Transmission of Acquired Characters.. 



It is difficult to understand how anyone well acquainted 

 with Darwin's works can come to any other conclusion 

 than that he firmly believed in Lamarck's principle of the 

 transmission of characters acquired by use. 



Two clear examples may be cited from " The Descent 

 of Man " (second edition) : — 



(i) "As the voice was used more and more the vocal 

 organs would have been strengthened and perfected 

 through the principle of the inherited effect of use " 

 (P- 87). ^ 



(2) " There is no more improbability in the contmuea 

 use of the mental and vocal organs leading to inherited 

 changes in their structure and function, than in the case 

 of handwriting, which depends partly on the form of the 

 hand and partly on the disposition of the mind ; and 

 handwriting is certainly inherited " (p. 88). 



In this matter Darwin was a true disciple of the great 

 French naturalist to whom Prof. Judd refers with such 

 scant respect. E. A. Parkyn. 



January 30. 



I REGRET that your correspondent should imagine that, 

 in writing the words "poor old Lamarck," I showed 

 " scant respect " for the great French naturalist. On the 

 contrary, I desired to express the deep sympathy I felt for 

 this grand pioneer in evolution, who, in old age and blind- 

 ness, found his splendid achievements, for the time being, 

 discredited by the work and arguments of his successful 

 rival, Cuvier. In the little book which has given rise to 

 this correspondence, I have insisted upon the splendid 

 contributions of Lamarck, not only to botany and zoology, 

 but also to geology, and have shown how the hostility 

 towards his work, felt at first by Lyell and Darwin, was 

 in the end modified, and his great merits acknowledged 

 by both of them. 



I quite agree with your correspondent that the passage> 

 he quotes — and many similar ones may be cited — show 

 that Darwin accepted the Lamarckian views as to the 

 transmission of acquired characters to a certain extent. 

 Darwin's tendency was, however, to insist that individual 

 variations were always "slight" or "exceedingly little," 

 to use his own words In the passage to which reference 

 has been made in the " Origin of Species," it would 

 almost seem that he suggests that " variation " had been 

 used in two different senses by authors — variations that 

 could be transmitted and variations that could not be 

 transmitted — and that he demurs -to the distinction. I 

 agree with Prof. Meldola, however, in thinking that, in 

 all probability, the view put forward by Prof. Weismann 

 in 1885, that no acquired character is directly inherited, 

 never fairly came under Darwin's consideration. 



In discussing questions of this kind, it is important to 

 realise, so far as is possible, what was the current opinion 

 at the time Darwin wrote. Now Baron Cuvier, his 

 brother Frederick, and their followers — whose writings 

 so greatly influenced naturalists in the early years of the 

 nineteenth century — all freely admitted the transmission, 

 by inheritance, of acquired characters, habits, and instincts 

 in domestic animals like dogs ; what they denied was th.-it 

 any of the variations so transmitted, so far a« the experi- 

 ence of 2000 years showed, were of a fundamental 

 character. 



That Darwin not only accepted the idea of the trans- 

 mission of acquired characters, but even speculated on 



