I20 



NATURE 



[November 23, 191 1 



increase of, the sensory cells. Disturbance of this equality 

 ><ive8 rise to colour-markings. Apparently Dr. Kobclt does 

 not believe in protective coloration. 



The Purdue University Experiment Station has taken 

 a leaf out of the business man's book, and freely advertises 

 its results amonjj farmers. The Bulletins, a number of 

 which are to hand, are written in a manner likely to 

 attract, and demonstrate that the yield of maize can be 

 considerably increased on the ordinary farm without a 

 great cxp<'nditurc, but solely by the adoption of improved 

 varieties or better fertilisers. New crops have been intro- 

 duced, and improved and more economical rations have 

 been drawn up for dairy stock. 



We have received from the United States Department 

 of Agriculture, Bureau of Entomology, catalogue by E. R. 

 Sasscer of recently discovered Coccidae and by D. Moulton 

 of the North American Thysanoptera, and also an anno- 

 tated bibliography of the Mexican cotton-boll weevil by 

 F. C. Bishopp. Publications of this type are extremely 

 valuable in enabling investigators to find their way through 

 the appalling number of entomological publications that 

 are put out at a rate probably unequalled in any other 

 subject. 



The National Geographic Magazine for September is 

 largely devoted to two studies of Troglodytes, one by Mr. 

 F. E. Johnson describing those of southern Tunisia, the 

 second by Miss E. H. Brewer the cave-dwellers in Cappa- 

 docia. Some French officers divide the Tunisian Troglo- 

 dytes, whose presence in that region is noted by the 

 historian Sallust into three groups : those living in excava- 

 tions in the ground, those occupying caves or holes in the 

 hillside, and thos* living in houses superimposed one upon 

 the other, the higher chambers being reached by precarious 

 staircases or stones projecting from the walls. The Troglo- 

 dytes in the Uskub Valley in Asia Minor occupy holes 

 excavated in curious rock cones. Prof. Sterrett, of Cornell 

 University, who has studied them, believes that this form 

 of dwelling dates so far back as the Hittite period. Both 

 these accounts oi two remarkable races are illustrated by 



series of admirable photographs. 



In the Zeitschrift der Gesellschaft jur Erdkunde (No. 7) 

 Dr. A. Riihl discusses the part played by isostasy in the 

 formation of peneplains. He considers that when an 

 elevated land mass is subjected to long-continued erosion 

 the isostatic equilibrium is destroyed, and as a result, after 

 a greater or less period of time, a new upward movement 

 will take place, but to a less extent than originally. Local 

 conditions will determine at what stage these isostatic 

 movements will occur. The development of the earth's 

 surface would not be a continuous operation, but rather 

 one strongly periodic in character in which short periods 

 of active orogenetic and epeirogenetic movement would 

 be succeeded by relatively long periods of erosion. 

 Orogenetic movements occurring would cause fracturing of 

 the earth's crust, and eroding agencies would become 

 active, removing material and redepositing elsewhere. 

 This will destroy the isostasy, and sooner or later a warp- 

 ing or tilting of the whole land mass will occur. 



Part iii., vol. xli., of the Records of the Geological 

 Survey of India contains the usual annual statistics of the 

 mineral production of India, the year here dealt with being 

 1910. Upon the whole, the production is just about 

 stationary, the value of the output showing an increase 

 only of some 12,000/., whilst its total is 7,700,000/. The 

 principal item, as before, is coal; the total output is just 

 over 12 millions of tons, showing an increase of about 

 NO. 2IQ£;, VOL. 881 



177,000 tons over 1909: on the other hand, prices h.ivr 

 fallen again to about what they were before the boom of 

 1907-8, and may be looked upon as at about a normal 

 level. The industry is evidently in a sound condition ; th^ 

 output per miner shows a satisfactory increase, and ex- 

 ports have gone up and imports have gone down by 43 

 and 36 per cent, respectively. Owing to the above- 

 noted fall in price, ihf v.-ilu*. of the coal output in 1910 

 is 324.32 iZ. lower li .09; but, as explained, this is 



a healthy symptom . the coal industry is concer: "H 



The next most valuable output on the list is that of i 

 which is practically stationary at 2,200,000/. These iwi, 

 minerals are by far the most important amongst Indian 

 mineral products, accounting for about three-fifths of the 

 total value. The production of manganese ore shows a 

 fair increase, the total for 19 10 being just over 800,000 

 tons ; prices were also rather better than they were in the 

 previous year, so much so that whilst the quantity pro- 

 duced was increased by 20 per cent., its value was increased 

 by no less than 40 per cent. The production of both mica 

 and petroleum has fallen off during the year under review. 

 Upon the whole, it may be said that whilst not chronicling 

 any brilliant results, the statistics before us show a steady 

 progress in the mining industry of our Indian Empire. 



The excessive rains of Saturday and Sunday last have 

 occasioned considerable and extensive floods at many places 

 in the south and east of England, and in Kent and Sussex 

 a great deal of land is under water. The Weather Report 

 issued by the Meteorological Office for the week ending 

 November iS shows that the total rainfall for the period 

 was largely in excess of the average over the entire 

 kingdom. The heaviest falls occurred in Scotland and 

 Ireland, where in parts the rainfall for the week was about 

 three times the average amount. Falls of more than an 

 inch in twenty-four hours occurred in all parts of the 

 kingdom ; and at Worthing the measurement for the three 

 days ending November 18 was 327 inches. The autumn 

 rainfall for the eleven weeks commencing with September 

 is now in excess of the average in all districts except in 

 the north and west of Scotland, the north-east of England, 

 and the Midland counties. The greatest excess for the ; 

 autumn is 3-00 inches in the Channel Islands, which is ^ 

 followed by 285 inches in the south of Ireland and 273 

 inches in the south-east of England. The greatest 

 deficiency of rain since the commencement of the year is 

 656 inches in the Midland counties, where the aggregate 

 fall, so far, is only 1653 inches. The temperature last I 

 week was largely in excess of the average in all thel 

 English districts, the excess amounting to nearly 5° in the 

 east of England. The duration of bright sunshine was 

 generally deficient. 



The meteorological chart of the North Atlantic for 

 November issued by the Deutsche Seewarte gives an 

 interesting account of a hurricane experienced on July 12 

 in the South Atlantic, near lat. 30° and long. 30°, by 

 four out ot five sailing vessels which left Chilian ports 

 between May 17 and June 14, the tracks of which are 

 laid down for the whole voyage to the English Channel. 

 It is noteworthy that the storm occurred with a relatively 

 high barometer ; the synoptic charts drawn for July 10-13 

 show that a shallow depression lay over the coast of central 

 Brazil on July 10, and that on the following day it had 

 divided into two parts, the centre of one being on the , 

 coast in 20° S. and the other in about 26° S., long. 39° W. 

 From the chart of July 12 it appears that the two systems 

 had coalesced, ard had travelled in a south-easterly direc- 

 tion. The atmospheric conditions are considered to be very 

 striking (notwithstanding that it was the southern winter). 



