March 30, 19 16] 



NATURE 



107 



March and June, she achieved some really useful work. 

 The unneighbourly character of the waterhen has 

 long been recognised, but few, probably, realise the 

 pugnacity it displays when fighting for territory or 

 ft-hen driving off trespassers when that estate has 

 Ijeen won. The true character and the importance of 

 :his aggressiveness has only recently been realised, 

 [laving been first clearly demonstrated in the case of 

 Lhe British warblers by Mr. H. Eliot Howard. Until 

 then the battles between males had always been re- 

 ^[^arded as contests between rival males for the pos- 

 session of females. Miss Turner's observations in 

 :his article entirely bear out the newer interpretation. 



In the forest of Soigne, at the gates of Brussels, 

 Belgium possesses two Government arboretums, 

 arranged on the group system, planted with exotic 

 :rees under forest conditions. These were founded 

 ibout twenty-five years ago, and, conditions being 

 /er\- similar to those which obtain in England, they 

 ifford useful object-lessons, possibly very little known, 

 ivhich should be studied by British foresters. For- 

 :unately, these arboretums were visited by Mr. D. E. 

 Hutchins, formerly principal forest officer in British 

 East Africa, in the summer of 1913, and his account 

 s published in the Transactions of the Royal Scottish 

 \rboricultural Society, vol. xxx., pt. i, of January, 

 [916. Among trees which will not grow in Belgium 

 nay be mentioned Sequoia se'mpervirens and many 

 [apanese trees which require a heavy rainfall, Douglas 

 ir is the fastest-growing conifer in both arboretums, 

 ind among the oaks Ouercus rubra has given the best 

 esults. Details of the growth of the various trees, 

 vvith girth measurements and age, are given in all 

 :ases. 



Prof. A. Henry contributes an illustrated article 

 m the black poplars to the Transactions of the Royal 

 Scottish Arboricultural Society, vol. xxx., January, 

 [916. He deals especially with the wild European and 

 -ast North American species and their various forms 

 and hybrids. The American species Populus deltoidea 

 sears cilia on the margins of the leaves, and glands 

 )n the base of the leaf in front, and the flowers have 

 fo-60 stamens and 3-4 stigmas. In the European 

 >oplar P. nigra the leaf characters of the American 

 slants are absent, and the stamens are only 12-25 3"*^ 

 itigmas 2. It is remarkable that the European 

 species, though well known to the pre-Linnaean British 

 sotanists, was named by Michaux from introduced 

 species growing on the banks of the Hudson and in 

 Sew York City. The Lxsmbardy poplar is only a 

 ;port from this species, and originated probably as 

 i single tree between 1700 and 1720 in Lombardy, 

 ind practically all the examples are males. The only 

 cnown female Lombardy is at Kew, and its history is 

 inknown. The numerous hybrid poplars are described 

 n detail, and their value as timber trees is discussed. 

 >ome vigorous hvbrids— e..^., P. generosa— have been 

 Jroduced by Prof. Henry. I 



Mr. Carlos Ameghino has contributed to Physis 

 ^01. u., No. 9, pp. 36-^) a useful French abstract of ' 

 lis important memoir on a femur of the extinct ungu- 

 ate loxodon, which seems to have been penetrated 

 luring life by an implement of quartzite, and suggests 

 ne great antiquity of man in the Argentine region of 

 >outh America. The Toxodon is considered to be of a 

 .mall species^ older than the Pampean formation, per- 

 aps even Pliocene, and the bone was found in a 

 leposit at Miramar, which mav well be of this age. 

 ine quartzite implement is actually embedded in th« 

 rreat trochanter of the femur, where the growth of 

 >one has partly enveloped it. 



-NO. 2422, VOL. 97] 



' Prof, R. A. Daly, of Harvard, has stated his views 

 as to the "Origin of the iron ores of Kiruna" in a 

 memoir issued by the Nordiska Bokhandel of Stock- 

 holm as part of the Vetenskapliga och praktiska 

 tindersokningar i Lappland (1915). The visit of 

 many members of the International Geological Con- 

 gress of 1910 to the magnetite mountain of Kiiruna- 

 vaara, under the guidemce of Herr Lundbohm, aroused 

 wide interest in the theoretical questions connected 

 with the massive band of ore. Prof. Daly expresses 

 himself with caution, but he regards the por- 

 phyritic igneous rocks as originally intrusive in the 

 form of a laccolite, the uptilting of their sheets being 

 due to later earth-movement. The magnetite became 

 separated, probably by gravitation, from the igneous 

 magma, and even the small and often angular blocks 

 of magnetite in the quartz-porphyry are held bv the 

 author to be local segregations, akin to the main ore 

 body, and not inclusions. 



On October 3, 1915, a great earthquake was re- 

 corded shortly after 7 a.m. at Eskdalemuir and other 

 observatories in this country. The epicentre was esti- 

 mated to lie in one of the western United States. 

 It now appears that this earthquake must have been 

 one which occurred in Pleasant Valley, Nevada, at 

 10.54 P-r"- (Pacific standard time) on October 2, and 

 is described by Mr. J. Claude Jones in the Bulletin of 

 the Seismolopcal Society of America (vol. v., 1915, 

 pp. 190-205). If it had occurred in a populous dis- 

 trict, the earthquake would have ranked as one of 

 the destructive earthquakes of the world. It disturbed 

 an area 800 miles long, from north to south, and 

 650 miles in width, an area which does not differ 

 much in extent from that affected by the Californian 

 earthquake of 1906. Pleasant Vallev runs in a 

 southerly direction from about 40 miles south of 

 Winnemucca. On the east side, it is bounded by the 

 southern half of the Sonoma Range, along the 'base 

 of which, for a distance of 22 miles, Mr. Jones traced 

 a fresh fault-scarp, nearly vertical, and varying in 

 height from 5 to 15 ft. The movement along this 

 fault, which caused the earthquake, was the latest 

 of a series responsible for the elevation of this part 

 of the Sonoma Range. 



Messrs, Edward St.\nford, Ltd., have just added 

 two new maps (Nos. 16 and 17) to their series of war 

 maps. No. 17 is a map of the British front in France 

 and Flanders, and is on a scale of half an inch to 

 a mile; it extends from Boesinghe bevond Ypres on 

 the north to Bray-sur-Somme on the' south, and is 

 coloured on the layer system, contours being shown 

 at 125 and 250 ft. It thus contains the whole of the 

 70 miles line of front now held by us. The other map 

 (No. t6), also coloured on the laver svstem, embraces 

 the whole of the troubled districts ' in the Balkan 

 Peninsula, including the mouths of the Danube and 

 Constantinople, Salonica, Belgrade, and Seraievo 

 The scale is 18 English miles to i in. 



The relation between cirrus directions as observed 

 in Melbourne and the approach of various storm 

 systems affecting Victoria is the subject of Bulletin 

 No. 10 of the Commonwealth Bureau of Meteorology. 

 Mr. E. T. Quayle records the direction of movement 

 of cirrus clouds in advance of the various tvpes of 

 cyclonic depressions which affect Victoria and finds 

 close correlations between these and the 'distance of 

 the trough of the depression. Thus, in the case of the 

 commonest type of depression in Victoria, the so-called 

 .■\ntarctic depression, observations indicate that cirrus 

 movements to the south of west are associated with 

 a trough more than 700 miles away, and north of west 



