November ii, 1920] 



NATURE 



355 



old method of removing the larvae from the trees 

 with the aid of a pocket-knife, a narrow chisel, and 

 a piece of wire. It is claimed that two men, on an 

 average, with an insignificant expenditure for tools 

 and materials, should be able to "worm" 500 trees 

 per diem. Ordinary white-lead paint is a cheap and 

 effective method for preventing the females from 

 ovipositing on the bark. . 



The important question of the control of the cotton- 

 boll weevil by means of poison is dealt with by 

 Messrs. B. R. Coad and T. P. Cassidy in Bulletin 857 

 (1920) of the U.S. Bureau of Entomology. Exter- 

 mination of the species is not attempted, the result 

 aimed at being a sufficient reduction of the weevil 

 infestation to permit of the production of a full cotton 

 crop, .\bout 60 per cent, of the squares which appear 

 on the cotton plant fail to mature as bolls, and are 

 normally shed at some time during their develop- 

 ment. It has been found that up to a certain point 

 the first shedding due to boll-weevil attack merely 

 takes the place of this perfectly normal shedding, 

 which would be encountered even if the weevils were 

 absent. The system of poisoning advocated is in- 

 tended to keep the weevils controlled to such a degree 

 that they will not be able to do more than offset the 

 above-mentioned shedding. The authors advise dust- 

 ing the plants with calcium arsenate at the rate of 

 5 lb. per acre. In order to avoid injury to the 

 foliage the powder should not contain more than 

 075 per cent, of water-soluble arsenic oxide. It appears 

 safe to assume that, with fertile soil and a fairly 

 severe weevil infestation, average gains of 500 lb. or 

 more of seed cotton per acre may be expected from 

 the treatment advocated. 



Wb have received a copy of the Mauritius Almanac 

 for 1920, published by the Mauritius Stationery and 

 Printing Co. It is a large volume containing a mass 

 of statistical and descriptive matter on all aspects of 

 the life of the colony. The account of the agriculture 

 is particularly full and interesting. There is a general 

 map of the whole island, and another showing the 

 distribution of rainfall. 



Thb results of some oceanographical researches on 

 the coast of South-West Africa are published by the 

 Deutsche Seewarte in Archiv, No. i, vol. xxxviii., 

 the first part of this publication which h.Ts appeared 

 since 1915. The work, which was carried out by the 

 \l&we so long ago as October, 191 1, to July, 1913, 

 includes the investigation of depths and sea tem- 

 peratures along the coast between the Orange and 

 Kunrne Rivers seawards as far as the 3oo-metre 

 contour. The results are discussed by Dr. A. Franz, 

 and include charts of the depths, water, and 



': air-temperatures. There Is also a section dealing 

 with the distribution of pressure and winds. The 

 work is particularly interesting in relation to varia- 



1 tion in the strength and temperature of the Benguela 



K current. 



f 



Tm degree of inaccessibility of various parts of 

 he Arctic regions has a direct bearing on future 

 tploration. Mr. V. Stcfansson has an article on 

 NO, 2663, VOL. 106] 



this subject, accompanied by a map, in the September 

 issue of the Geographical Revie-ur (vol. ix.. No. 9). 

 By measuring distances of 500 miles northward along 

 the meridians from the more northerly points attained 

 by various exploring ships, an area of comparative 

 inaccessibility is found to remain. The distance of 

 500 miles is chosen, on the basis of Peary's journey 

 from Cape Columbia to the Pole, as a fair maximum 

 possible with dog-teams from the base of supplies. 

 By these estimates the " pole of inaccessibility " is 

 found to be at latitude 83° 50' N., longitude 160° W. 

 Various modifying factors must be borne in mind. 

 Open leads or heavy pressure ridges are great im- 

 pediments to sledge travelling in several parts of the 

 Arctic basin, while the action of currents may nullify 

 advance or, if known and taken advantage of, may 

 greatlv facilitate progress. The question of food 

 supoly, if the traveller is "living off the country," 

 also influences the problem. Certain areas of .Arctic 

 ice arc known to be almost devoid of seals. These 

 deserts must be avoided or crossed hurriedly. But 

 .Mr. Stefansson believes that the well-known drift 

 across the Pole carries to this region, least accessible 

 to man, a certain number of seals from the Beaufort 

 Sea, where they are abundant. 



.\s previously recorded in Nature {.\ugust 23, 1917, 

 p. 510), certain plant remains found in the wide 

 tract of sandstones and conglomerates on the west 

 coast of Norway led Nathorst to assign those rocks 

 to the Middle Devonian. Some fish remains found 

 since, and " now described by Dr. Johan Kiaer 

 (Bergens Museums Aarbok, 1917-18, 2 Hefte, 1920), 

 fully confirm this conclusion, and, though incapable 

 of specific determination, warrant a comparison of the 

 Norwegian rocks with the upper part of the great 

 Orcadian group as displayed in the north of Scot- 

 land, and particularly in the more closely adjacent 

 Shetlands. There were at least two kinds of ganoid 

 fishes (apparently Diplopterus and Tristichopterus) 

 existing in large numbers, and, whether they fed on 

 other fishes or not, their presence implies the -exist- 

 ence of a large animal and plant life for their main- 

 tenance. Some of the plants are regarded by Nathorst 

 as aquatic, and tracks of some crustacean have been 

 observed. The present discoveries will doubtless load 

 to further investigation of these rather inaccessible 

 Devonian regions, and we may hope that remains of 

 other animals will before long be found. 



Parts i and a of vol. vi. of the Proceedings of the 

 Indian .Association of Science contain together »ight 

 papers which extend to 112 pages. .Mthough the 

 papers cover most branches of physics, investigations 

 connected with the behaviour of musical instruments 

 are most popular. Amongst these one by Prof. 

 Raman on the variation of the bowing pressure with 

 the pitch of the note, with the part of the string 

 bowed, and with the speed of bowing in a violin 

 may be noted. The observations wore made with a 

 violin moved mechanically to and fro at a constant 

 speed over an iron track, while above it was sus- 

 pended a bow in a balanced frame which allowe<l the 

 prrssurc on the string to be varied. If the position 



