October 7, 1920] 



NATURE 



189 



1588, while Linnaeus mentions the rare half-hoary 

 senii-incana in 1762. Crosses of these forms produce 

 a series of intermediate factorial combinations, in- 

 1 luding: a type with a single hair on the tip of each 

 leaf. It is concluded that the " factor " for a par- 

 ticular degree of hairiness represents a particular 

 iindition of physiological equilibrium subject to 

 • nvironmentally produced fluctuations. 



In the Journal of the Royal Microscopical Society 

 (1920, part 2) Mr. T. E. Wallis describes a method 

 <if quantitative microscopy by use of Lycopodium 

 spores. By a sufficiently thorough mixing of the 

 materials to be tested with the spores and by the use 

 "f a suitable suspending medium, the author finds it 

 jiossible, by making a number of counts of the spores 

 in different fields of view, to obtain results of an 

 order of accuracy equal to many of those obtained 

 by chemical operations both qualitative and quantita- 

 tive. .As examples are cited the determination of the 

 jiroportion of maize-starch that had been added to 

 inie ordinary wheat-flour, and the determination of 

 he number both of starch grains per milligram of 

 maize-starch and of pollen-grains per milligram of 

 insect-powder; the last-mentioned supplies an index of 

 the value of the powder. 



Hr. W. Mackie has shown that monazite is widely 

 distributed in the granites of the North of Scotland, 

 and it has now been found by Dr. .A. Gilligan in 

 almost all the beds of the Millstone Grit of Yorkshire, 

 doubtless derived from this northern source ("The 

 Petrography of the Millstone Grit of Yorkshire," 

 <juart. Joum. Geol. Soc., vol. Ixxv., p. 271, 1920). 



Thk " Final Report of the Work of the Commission 

 on .Munition Resources, Canada " (Toronto, 1920), 

 besides useful notes on recent prospecting, contains 

 (PP- 5^88) xm account of trenches made for the 

 investigation of bog-manganese ore, which may be 

 of service to those interested in such deposits in 

 Ireland. There seems not much hope of competition 

 betwe<;(i the bog material and the hard ores of the 

 ordinary mines. We have yet to learn how far selec- 

 tive action by bacteria is responsible for the precipita- 

 tion of manganese oxides in swamps. Mr. Uglow's 

 practical report naturally leaves the matter open. 



Dr. R. S. Lull describes in the American Journal 

 of Science (vol. 1., p. 83, 1920) two "new Ter- 

 tiary .\rtiodactyIs " from remains discovered in 

 Nebraska in 19 14 by an expedition from Yak? under 

 his guidance. The deposits are of Late Miocene or 

 Early Pliocene age. A very pleasing restoration \h 

 given of a new antelope, Metomeryx gracilis, of 

 : which abundant material has been obtained, includ- 

 tnfi nineteen skulls, both male and female. The 

 mc, meaning "wandering ruminant," is chosen on 

 ount of the migratory powers indicated by the 

 Icacy of the limbs. The limb-bones are, indeed, 

 icrally broken. 



From the General Report of the Survey of India 



:or 1918-19 wc learn that the curtailment of work 



ing to war conditions continued, several survey 



irtics being engaged in Mesopotamia, East .Africa, 



■-* elsewhere out of India. Of the topographical 



NO. 2658, VOL. 106] 



map on the one-inch scale 57 sheets were published 

 during the year in place of the pre-war figure of 

 150 to 200. .About 1500 one-inch sheets have no*r 

 been published out of a total of 6218. Thirty half-inch 

 and II quarter-inch, or "degree," sheets were pub- 

 lished. The half-inch map is now the tactical map 

 of India, and 177 of the 630 sheets are available. 

 The "degree" sheets are making slower progress, and 

 their total is now only 52 out of 450. No further 

 sheets of La Carte Internationale (i : 1,000,000) ap- 

 peared during the year, but two sheets of the India 

 and .Adjacent Countries Series (i : 1,000,000) were 

 published. The report includes complete indices of 

 all sheets published by the Survey of India. 



The Mines Branch of the Department of Mines of 

 Canada has just issued a valuable monograph on 

 graphite, written by Mr. Hugh S. Spcnce. It describes 

 in detail the important Canadian occurrences of this 

 mineral, and also reviews all other known sources of 

 supply throughout the world. It is interesting to note 

 that in 1913 Germany and .Austria together produced 

 practically one-half of the world's total supply, but 

 that since then the .American output has been nearly 

 trebled. .An interesting account is given of the various 

 methods used for the concentration of graphite, for 

 which purpose the flotation process appears now to be 

 the most favoured, and the manufacture of artificial 

 graphite is also described. .An important section is 

 devoted to the industrial applications of graphite ; it is 

 stated that the world's production of natural graphite 

 is utilised in approximately the following proportions : 

 For crucibles, 75 per cent. ; for lubricants, 10 per 

 cent. ; for pencils, 7 per cent. ; for foundry facing and 

 stove-polish, 5 per cent. ; and for paints, 3 per cent. 

 The method of manufacture of all these articles is 

 described, as well as that of others not included in 

 the above list, such as graphite brushes for dynamos 

 and motors, graphite electrodes, graphite for dry bat- 

 teries, for electrotyping, and for various less im- 

 portant purposes. The monograph should prove 

 valuable to all interested in the mining of graphite 

 or the manufacture of graphite articles. 



The United States Geological Survey has just 

 issued an elaborate monograph on the economic 

 geology of Gilpin County and .-idjacent parts of Clear 

 Creek and Boulder Counties, Colorado, bv Mr. E. S. 

 Bastin and Mr. J. .M. Hill. This district includes 

 most of the mining camps of Colorado that are pro- 

 ducing minerals of economic importance, including 

 the well-known auriferous pyritic ores of Gilpin 

 County, the gold and silver veins of Clear Creek 

 County, the lead ores of I>«adville, the telluric gold 

 ores of Telluride, and many others. In addition to 

 gold, silver and lead ores, the district here described 

 produces also ores of zinc, copper, uranium and 

 tungsten, the goW production being, however, 

 economically by far the most important. The mono- 

 graph describes the general topography of the area, 

 spoken of here as the Central City quadrangle; the 

 geology is described in detail, particular attention 

 b<-ing devoted to the igneous rocks, amongst which 

 the monzonites are the most important. Chapters ar« 

 devoted to the economic geology and to the general 

 features and origin of the various oro deposits, each 



