43^ 



4^ATUm 



[December i, 192 i 



last month has threatened the very existence of many 

 distinguished men in universities of that country. 



The Universities' Committee has also taken on 

 the further responsibility of endeavouring to raise 

 funds for the relief of men of learning and students 

 in Russia. In careful consultation with Dr. Nansen, 

 the committee is establishing those links in Russia 

 which shall ensure a wise distribution of the funds 

 subscribed. Dr. Nansen has issued a personal appeal 

 to the universities of the world to help to save from 

 extinction the rapidlv diminishing numbers of men 

 in Russia who have been able to go through the 

 ordeal of suffering to which many of them have been 

 subjected during the past few j^ears. May I appeal 

 to readers of Nature for their support of the work 

 of the Universities' Committee? 



Further detailed information, which for lack of 

 space cannot be given here, Miss Iredale, the 

 organising secretary, will always be glad to send on 

 application to anv reader. 



In a letter to' graduate members of the British 

 universities on behalf of the men of learning of 

 Austria an urgent appeal has been made over the 

 following signatures of distinguished representatives 

 of learning : — 



William Bragg, Gilb'^rt Murray, 



Brvee, E. Rutherford, 



A.'S. Eddington, M. E. Sadler, 



Richard Gregory. Arthur Schuster, 



Haldane of Cloan, Napier Shaw, 



Frederic G. Kenvon, A. E. Shipley, 



Walter Lock. ' George Adam Smith, 



Donald Macalister, Ernest H. Starling, 



Charles J. Martin, J. J. Thomson. 



Henrv A. Miers, 



Maurice de Bunsen, 

 Chairman, Universities' Committee. 

 Fishmongers' Hall, London Bridge, E.C.4, 

 November 21. 



Ophion luteus. 



I BEG to thank Dr. Gahan and Dr. Stenton for 

 their notes on this insect in Nature of November 24, 

 p. 403. I am well aware of the importance of pre- 

 cision in recording the behaviour of any animal and 

 any other natural phenomenon ; wherefore I was 

 specially careful to ascertain from the persons who 

 had been stung by Ophion in my house whether the 

 insects had received any provocation. In most of 

 the cases brought to my notice (numbering three 

 or four in each of the last five years) the person stung 

 was asleep, and may semi-consciously have _ made 

 some movement that irritated the fly. But in the 

 case I mentioned as happening last August, the young 

 lady was reading in bed and felt the sharp stab on 

 her arm before she saw the fly. 



Our experience of the results of the sting differs 

 from that of M. R. du Buysson as quoted by Dr. 

 Gahan ; but, of course, individuals differ very much 

 in susceptibility to poisonous stings. The persons 

 stung in mv house, so far as has been brought to 

 my notice, 'were all voung, except one lady^ more 

 than forty vears of age. In her case, as In the 

 others, the sting was followed by a painful and 

 peculiarly hard swelling which did not subside in 

 less than twentv-four hours. 



Dr. Stenton asks whether care was taken to 

 identify the species of Ophion. I sent specimens for 

 identification to both Dr. Gahan and Mr. J. M. 

 Gordon, who concurred independently in pronouncing 

 the flv to be Ophion liiteus. 



■ Herbert Maxweix. 



Monreith, Whauohlll, Wigtownshire, N.B. 

 NO. 2718, VOL. 108] 



The "Zoological Record." 



The Zoological Record, which was founded in 

 1864 by English zoologists, has been issued regularly 

 ever since, and contains each year a complete biblio- 

 graphy of all publications connected with zoology. It 

 is now the sole work of the kind, and is invaluable 

 to all workers in every branch of zoology. 



Previous to 1914 the Zoological Record formed part 

 of the " International Catalogue of Scientific Litera- 

 ture," and was issued under the joint responsibility 

 of the Royal Society and the Zoological Society. As 

 the Royal' Society found itself unable to proceed with 

 the volumes of the " International Catalogue " after 

 the issue for 1914, the Zoological Society has under- 

 taken to prepare and issue the volumes for 1915-20 

 inclusive at its sole financial risk. 



It is the wish of the Record Committee of the 

 Zoological Society to continue the publication of this 

 most useful work, but it is obvious that it can- 

 not expect the society to undertake the heavy 

 financial liability Involved in publication, unless^ it 

 receives reasonable support from working zoologists 

 both at home and abroad. 



I hope, therefore, that all working zoologists who 

 agree with me that the suspension of the _ publica- 

 tion of the Record would have a most disastrous 

 effect on the progress of zoology will either subscribe 

 themselves, or will urge the librarians of the institu- 

 tions with which they are connected to do so. 



A prospectus and "form of subscription either for 

 the whole or separate divisions of the Record can 

 be had on application to the Zoological Society. 



W. L. Sclater, 

 Editor, Zoological Record. 

 Zoological Society of London, London, N.W.8. 



Reflection from Cylindrical Surfaces. 



The cone of light reflected from a cylindrical sur- 

 face described by Mr. Shaxby in Nature of Novem- 

 ber 17, p. 369, is discussed in Tait's elementary 

 treatise on Light. 



•A related phenomenon, also mentioned in the same 

 work, the explanation of which is readily deducible 

 from the above, is of interest. I refer to the circle 

 of light seen bv reflection of a distant point source 

 from a bundle 'of cylindrical surfaces. The surfaces 

 may be of anv form, the condition being that their 

 generating lines must all be parallel to one another. 

 The locus of points of reflection is then a conical 

 surface containing the source, v/ith its apex at the 

 eye of the observer. The axis of the cone is parallel 

 to the generating lines of the surfaces. When the 

 line joining the 6ve to the source is parallel to these 

 lines, the circle reduces to a point coinciding with 

 the source ; when at right angles, the circle becomes 

 a great circle passing through the source. 



An evervdav illustration of this is to be seen in 

 the reflection 'of a distant street-lamp by the closed 

 roller shutters of a shop-window. The points of light 

 reflected from the corrugations form an arc of a 

 --ircle which If completed would pass through the 

 lamp. . . 



The circle of light seen when viewing a pomt 

 source through certain crystals Is evidently due to the 

 same phenomenon, the crystals presumably being 

 fibrous In structure or containing enclosures or cavi- 

 ties with cylindrical surfaces. Some years ago Prof. 

 S! P. Thompson submitted some crystals having this 

 property to a meeting of the Physical Society of 

 London. C. O. Bartrum. 



32 Wllloughby Road, Hampstead, 

 November 22. 



