40 



NA TURE 



[November 14, 1907 



for towns in the tropics consists (i) in the rcmovnl of 

 mosquito-breeding waters ; (2) in the treatment of old 

 cases of malaria with quinine ; and (3) in the protection, 

 as an additional safeguard, of hospitals, barracks, jails, 

 and as many houses as possible with wire gauze. To 

 these we must add, as insisted upon by Stephens and 

 Christophers, the principle of segregation of Europeans." 

 The campaign at Ismailia has been the most successful 

 one on record, so that in 1906 the Suez Canal Company 

 officially reported that " toute trace de paludisme a disparu 

 d'Ismailia." In this campaign the result is due to mos- 

 quito reduction, and also largely to cinchonisation. This 

 example is all the more conclusive because statistics have 

 existed for many years back. Successful and partially 

 successful results have been obtained from many other 

 districts, notably Klang and Port Swettenham, Hong 

 Kong and Khartoum, and especially at Havana and 

 Panama. Many of these results are hard to estimate on 

 account of the insufificient data. That malaria can be 

 stamped out — given the money — under almost any con- 

 ditions can hardly be doubted ; but for those who have 

 doubts an experiment carefully planned, with all statistics 

 carefully controlled and subject to criticism before, during, 

 and after the experiment, would do much to remove pre- 

 judices which still exist. 



The Department of Agriculture in the United r;ates has 

 for some time advocated the sowing of early varieties of 

 cotton in districts where the boll weevil flourishes. 

 Another measure for reducing the pest, recommended in 

 Circular No. 95, prepared by Mr. W. D. Hunter, consists 

 in uprooting the cotton plants in the autumn as soon as 

 the crop is cut off by the weevils ; many weevils are thereby 

 prevented from developing, and especially those which pass 

 the winter and attack the next season's crop. It is further 

 recommended that the plants be ploughed up and burnt. 



Mr. C. a. Barber has contributed to the Memoirs of 

 the Department of Agriculture in India, vol. i.. No. i, 

 the second part of his investigation of the haustorium of 

 Santalum album, the sandal-wood tree. The essential 

 parts of the sucker are the cortical folds with which it 

 grips the host root and the central core by which it pene- 

 trates. Vessels are developed around the core and in the 

 upper part of the sucker, but there is discontinuity 

 between them. No true bast is formed in the haustorium. 

 The inter-relation between parasite and host is often re- 

 markable. Sometimes the root is fiercely attacked, as in 

 the case of Cassia aiiriculata ; in other cases the parasite 

 is unable to penetrate, as in Zizyphus. The haustorium 

 may even attack another sandal root, when a fusion 

 results, or a great struggle takes place. 



The greater part of the last issue of the Kew Bulletin 

 (No. 9) is given up to an interesting account, communi- 

 cated by Prof. H. H. W. Pearson, of a journey from 

 Walfish Bay to Windhuk. The author distinguishes a 

 botanical area of Walfish Bay where Nicotiana glauca, 

 an Argentine colonist, and the native Tamarix articulaia 

 grow on the flats, and the cucurbitaceous plant 

 Acanthosicyos horrida inhabits the sand dunes. The last- 

 named exhibits a marvellous power of absorbing water and 

 storing it in the stems thickly coated with cork. The 

 dunes give place to a tableland, the "Namib," where 

 Zygophyllum Stapfii is prominent. This is also the re- 

 stricted habitat of Welwitschia. Further inland from 

 Usakos to Winterhuk an Acacia park forest occurs. In 

 the same volume the decade of " Diagnoses Africanae " 

 contains two new genera, Cordeauxia, a leguminous plant 

 from Somaliland, and Peglera, a genus referred doubt- 

 fully to the Rhizophoraceae. 



NO. 1985, VOL. 77] 



The Bulletin of the Italian Geographical Society, vol. 

 viii.. No. 10, contains a report on the establishment of 

 meteorological stations at the following towns in Asia 

 Minor : — Marash, Urfa, Diarbekir, Meserch, Calat 

 Scergat, and Babilonia. 



Further observations on the anomaly of the recession 

 and progression of Alaskan glaciers are published by Dr. 

 Otto Klotz in the Geographical Journal for October (vol. 

 XXX., No. 4). The "Johns Hopkins" glacier has receded 

 nearly seven miles during thirteen years, whereas the 

 adjacent " Grand Pacific " has receded only about three and 

 a half miles during the same period. Dr. Klotz emphasises 

 the need for more observations of the Alaskan glaciers. 



The disputed question of the appearance of icebergs near 

 the Orkney Islands in 1836 has been again raised by Prof. 

 O. Kriimmel in the Zeitschrift der Gcsellschaft fiir 

 Erdkunde, No. 7, 1907. Assisted by the marine super- 

 intendent of the Meteorological Office in London, Dr. 

 Kriimmel has published an extract from the log-book of 

 S.M.S. Cove which seems to prove conclusively that two 

 large icebergs were actually observed in the vicinity of the 

 Orkney Islands in January, 1836. 



An ingenious instrument, termed a horticultural hygro- 

 meter, has been designed by Messrs. Negretti and Zambra. 

 Buchan and Scott have shown that a knowledge of the 

 temperature of the dew point in the late evening would 

 enable gardeners and others to form a fair estimate of 

 the probable minimum temperature to be expected, as it 

 cannot easily fall below the dew point which existed at 

 nightfall. The instrument in question makes use of this 

 knowledge ; it consists of dry- and wet-bulb thermometers, 

 and of a cylindrical scale based upon the relation of the 

 dew point to the difference of the readings of the thermo- 

 meters. By turning the scale to correspond to this differ- 

 ence, it is seen at once from the position of the wet-bulb 

 reading upon it, without the use of tables, whether the 

 dew point is below freezing, and consequently whether 

 frost may be expected. So far, however, as regular 

 meteorological observers are concerned, we presume that 

 they would probably prefer to rely on the use of simple 

 hygrometrical tables. 



The thick fogs w'hich have prevailed over so large a 

 part of the country of late, and have been more than 

 usually dense in London for so early in the season, have 

 given prominence to the question of the dispersion of fog. 

 .•\ scheme invented by M. Demetrius Maggiora, by which 

 a series of atmospheric vibrations are set up by means of 

 explosions of acetylene or other gas in a strong steel 

 cannon about 60 feet high and 6 feet in diameter, has 

 been under the consideration of the Public Control Com- 

 mittee of the London County Council. Before committing 

 themselves to any action on the subject, the director of 

 the Meteorological Office, Dr. W. N. Shaw, F.R.S., has 

 consented to examine and report upon the proposal and 

 its suitability to the atmospheric conditions of London, and 

 a report on the subject is anticipated at an early date. 



Some South African Tardigrada form thn subject of a 

 paper by Mr. James Murray in the Journal of the Royal 

 Microscopical Society for October. The material for the 

 paper was received from Mr. W. Milne, of Uitenhage, 

 Cape Colony, in the form of gatherings of moss contain- 

 ing bdelloid rotifers. It yielded eight species of Echiniscus, 

 five of Macrobiotus, and the one known species of 

 Milncsium. Eight of the fourteen species were distinct 

 from any species previously known. 



