i8 



NATURE 



\Nov. 2, 1876 



of land and water ; (5) changes in the position of the earth's 

 axis ; (6) a variation in the amount of heat radiated by the sun ; 

 and (7) various temperatures of those regions of space through 

 which the solar system has moved. Discussing each of them, 

 Mr. Wood deals at greater length with the theory advocated by 

 Mr. CroII, arriving at the conclusion that, although the influence 

 of geographical conditions and currents is a powerful agent in 

 modifying climate, nevertheless the cause of the Glacial period 

 must have been a cosmical one ; that the cold of this period 

 seems to have fallen upon the earth while its axis was in its 

 present position ; and that nothing has yet been found to raise a 

 doubt as to the glaciation of the northern and southern hemi- 

 spheres having been synchronous. Mr. Wood inclines to admit 

 that it is to the sixth suggested cause, a diminution in the heat 

 emitted by the sun, that the probabilities incline. The discus- 

 sion of the geological facts connected with the latest changes of 

 climate is the main attraction of the paper of Mr. Wood. 



Capt. Allen Young's Arctic ship Pandora is back again, 

 all well. It will be remembered Capt, Young went out to 

 endeavour to communicate with the Arctic expedition, which he 

 met on its road home. 



Two shocks of earthquake were felt at Irkutsk and its neigh- 

 bourhood, on August 31 at 10 p.m., and on September 4 at 

 1.30 A.M. Both extended over a large region, and the last was 

 rather strong at Irkutsk. 



Two earthquakes are reported as having occurred in Germany 

 on October 14, the one near Kehl at 11 a.m., and the other at 

 Schopfheim between 8.30 and 9 P.M. The former extended over 

 Strasburg, Kehl, Kork, Auerheim, Zierolshofen, Leutesheim, 

 Linz, Diersheim, Rhein-Bischofsheim ; the direction was appa- 

 rently in a south-west-north-east direction. There were ihrte or 

 four shocks lasting about four seconds. The other earthquake 

 was to the north of Schopfheim, at Neuenweg and Gresgen, and 

 was of shorter duration than the former ; the direction was 

 apparently north-south. 



The African explorer, Eduard Mohr, writes to Dr. Nach- 

 tigal, under data August 28, of his arrival at St. Paul de Loanda. 

 Within eight days he was to proceed to Malange, on the eastern 

 limit of Angola, which he was to make his base of operations for 

 an exploring journey to the northern interior. 



In the Geological Section of the Helve'.ic Society of Sciences, 

 besides many interesting smaller communications, the following 

 larger contributions to geological science were made : — The 

 results of a thorough exploration of the earlier geological his- 

 tory of the Black Forest and of the Vosges, by Prof. Sand- 

 berger ; the results of explorations in the Argovian Jura, by 

 Prof. Muhlberg ; the results of explorations by M. Moesch in 

 the Bernese Alps, accompanied by a map of the mass of the 

 Faulhorn and of its neighbourhood ; a map on the scale of 

 1:250,000 of the glacial deposits of Switzerland, with full par- 

 ticulars as to the former extension of glaciers, their depths, 

 slopes, &c. , made by Prof. Favre ; and a very detailed map, on 

 a scale of 1:5,000, of the glacier of the Rhone, with all its 

 moraines, moulins, crevices, &c., constructed by M. Gosset, at 

 the charge of the Swiss Alpine Club. 



At the same meeting Prof. Sandberger presented his work 

 " Land- und Susswasser- Conchy lien der Vorwelt." The terres- 

 trial and fresh-water molluscs are described here in these geolo- 

 gical succession, beginning from the oldest formations. Being 

 very abundant in the Tertiary deposits, they have, as is known, 

 much contributed to settle the classification of these deposits. 



At the conversazione of the Chester Society of Natural 

 Science held last month, Mr. Cioss exhibited some specimens of 

 Drosera rotundifoUa which had been grown in Mr. Siddall's 



fern case, and which presented characters differing greatly from 

 those of the typical plant. The axis had elongated considerably 

 and bore a number of alternate leaves, quite green, with aborted 

 tentacles, and several of them showing buds produced on the 

 mid-rib. Some of the old leaves of the original plants placed 

 in the case for preservation also exhibited the phenomenon last 

 named. 



We have received from Dr. C. A. MacMunn an account of 

 the method he proposes for measuring and] comparing different 

 spectra with the spectrum microscope. In order to overcome 

 the difficulties due to the difference in the dispersion of different 

 prisms, he proposes to look upon the distance between the 

 Fraunhofer lines b and E as equal to 100, and to express the 

 position of all bands in relation to this scale. We, however, 

 think that it is very desirable not to multiply the already too 

 numerous arbitrary scales of this kind, and would strongly 

 advise him and all others who are studying this subject, to ex- 

 press their results in terms of wave lengths, since, as Mr. Sorby 

 has argued, that system alone has a true physical basis. 



The Bethnal Green Museum is becoming just now a great 

 centre of attraction to the multitudes from the numerous'interest- 

 ing collections illustrative of art and science now deposited 

 together. The former speak to the eye for themselves, although 

 the Secretary of the Department has taken care to provide admir- 

 able historical and descriptive cheap catalogues. But the scientific 

 and industrial collections require more carefully prepared aids for 

 study, and these are now being furnished by the Department in 

 illustrated manuals, published at a cheap price, written by 

 eminent authors, and on these no expense has been spared to 

 make them thoroughly practical and useful treatises upon the 

 subjects on which they treat. Messrs. Chapman and Hall, we 

 are informed will publish immediately for the Council of Edu- 

 cation and Department of Science, three of these works— 

 "Food, its Chemical Constituents and Uses," by Mr. A. W. 

 Chunt, F.C.S., Professor at the Royal Agricultural CoUci^r, 

 Cirencester; " Economic Entomology," by Mr. Andrew Mur- 

 ray, F.L. S., and "Animal Products, their Preparation, Com- 

 merce, and Uses," by Mr. P. L. Simmonds. 



The additions to the Zoological Society's Gardens during the 

 past week include a Cape Hyrax {Hyrax capensis) from South 

 Africa, presented by Mr. J. M. Thornton; an Ocelot {FelisJ>at' 

 dalis) from Honduras, presented by Mr. H. Fielding ; two 

 Norwegian Lemmings {Lemmus norvegicus) from Norway, pre- 

 sented by Mr. W. Duppa Crotch ; a Common Hangnest {Icterus 

 vulgaris) from South America, prestnied by Mr. J, T, Levett ; 

 an Alrican Cobra [Naia haje) from South Africa, presented by 

 the Rev. G. H. R. Fisk ; a Vervet Monkey ( Cercopithecus lalandii) 

 from South Africa, deposited ; two Indian Cobras [Naia tripti- 

 dians) from India, received in exchange ; a Merlin {Hypotriorchu 

 ccsalon), European, purchased. 



SEXUAL SELECTION IN RELATION TO 

 MONKEYS 



TN the discussion on Sexual Selection in my "Descent ot 

 ■*■ Man," no case interested and perplexed me so much as the 

 brightly- coloured hinder ends and adjoming parts ot certain moc- 

 keys. As these parts are more brightly coloured in one sex than 

 the other, and as they become more brilliant during the season of 

 love, I concluded that the colours had been gained as a sexual 

 attraction. I was well aware that I thus laid myselt open to 

 ridicule ; though in fact it is not more surprising that a monkey 

 should display his bright-red hinder end than that a peacock 

 should display his magnificent tail. I had, however, at that 

 time no evidence of monkeys exhib.ting this part of their bodies 

 during their courtship ; and such display in the case ot birds 

 affords the best evidence that the ornaments of the males are of 

 service to them by attracting or exciting the females. I have lately 



