;46 



NATURE 



[January 12, 191 1 



extent determined by climatic and soil conditions. The 

 author criticises the mycoplasm theory of Eriksson, which 

 refers mainly to the phenomena here described. 



A CATALOGUE of hybrid plants raised at Kevv during past 

 years is published in the Kew Bulletin (No. 9). The 

 three hybrid species of Cytisus are interesting, two being 

 ascribed to chance pollination by insects, while the third, 

 Cytisus Dallimorei, producing pale purple flowers, was the 

 result of an artificial cross between a variety of 

 C. scoparius and C. albus ; it received an award at the 

 Temple Show last year. Success has been attained with 

 several Rhododendron hybrids, notably a cross from 

 Rhododendron Fortunei, and two monophyllous Strepto- 

 carpus hybrids are recorded. A Strelitzia that flowered for 

 the first time during the winter 1909-10 was raised from 

 a cross made in 1893. 



The Agricultural and Forestry Department of the 

 Nyasaland Protectorate has issued its second annual report, 

 from which we learn that the past year has been one of 

 the most successful on record. A few years ago the only 

 industry of any importance was coffee ; when this failed, 

 the plantations were closed down. With the introduction 

 of cotton, tobacco, and rubber, the area of land under 

 cultivation has steadily increased, and at no time in the 

 history of the protectorate have such large areas of virgin 

 land been opened up for planting as at present. The 

 experimental work of the department consists in the 

 improvement of existing crops and testing of new crops 

 likely to be of value. Afforestation is also being under- 

 taken, the railway and tobacco industries having been 

 responsible for a large consumption of the native timber. 



The Agricultural Journal of India, vol. v., part iii., 

 contains articles on the cultivation of millet, jute, Cara- 

 vonica cotton, and bananas. The millet, Andropogon 

 Sorghum, is grown in the dry zone of Upper Burma, where 

 the yearly rainfall is from 20 to 25 inches, and rice will 

 not grow. The grain furnishes food for the natives, and 

 the leaves and stalks for cattle. Jute is grown on land 

 suitable for rice; in some districts it is possible to take 

 winter rice after jute, and thus to get two crops in one 

 year ; but this is not always possible, and in general it 

 may be said that the area under jute represents the loss 

 of so much land to rice. Caravonica cotton is a hybrid 

 tree cotton recently introduced, for which many excellent 

 properties were claimed. It is stated, however, that the 

 variety has not been a success, and, further, that no tree 

 cotton is known that will answer as a field crop. 



The need for phosphatic manures in all parts of the 

 world, and the rate at which their already high consump- 

 tion is increasing, makes it important that all known 

 phosphate deposits should be mapped as thoroughly as 

 possible. Should a phosphate famine ever occur, it would 

 be more serious than a coal or any other famine, as no 

 substitute of any kind is known. The United States 

 Department of Agriculture Bureau of Soils has recently 

 investigated the phosphate fields of Idaho, Utah, and 

 Wyoming, and published the results as Bulletin 69 of their 

 series. The deposits are considerable, and though they are 

 not yet extensively worked because of their distance from 

 markets, there is no doubt that they will become important 

 in future. It is recommended that steps should be taken 

 now to control the mining rights and to prevent waste of 

 the lower-grade deposits that will not at first be profitable 

 to work. 



Prof. Emile Chaix, Avenue du Mail, 23, Geneva, has 

 issued a circular letter, accompanied by a pamphlet, direct- 



NO. 2150, VOL. 85] 



ing the attention ' of geographers and geologists to the' 

 " .Atlas photographique des formes du Relief terrestre." 

 This work was organised by the ninth International Con- 

 gress of Geography in 1908, in accordance with a proposal 

 by Profs. Brunhes and Chaix, and subscriptions are now 

 asked for, so that a series of views may be prepared and 

 published. Prof. Chaix 's pamphlet furnishes the details, 

 and it will be possible to subscribe for 100 plates at half 

 a franc apiece, or single plates at one franc each. It is 

 estimated that the whole series required would be about 

 500 to 600 plates, their issue being spread over ten years. 

 The samples furnished give a picture about 13 cm. b\ 

 9 cm., and are of a geological rather than a geographical 

 character. The scheme, however, is a wide one, and we 

 may hope to see such subjects as typical cirques, alluvial 

 plains, and escarpments, illustrated from all parts of the 

 world. It is at present, for example, difficult to obtain 

 views of our own Cotteswold Hills, or the meanders of 

 the Severn, or the Hercynian ridges of southern Ireland. 

 The cooperation of scientific photographers is invited, and 

 it is to be hoped that geographical considerations will 

 prevail in the selection. 



In the meteorological chart of the North Atlantic Ocean 

 for January (first issue), published by the Meteorological 

 Committee, attention is directed to the displacement of tli 

 high-pressure system to the region of Madeira and North 

 Africa as one of the marked features in the daily weather 

 maps of December 8-14, 1910, embracing the North 

 Atlantic and adjacent shores. An enormous region of low 

 pressure, extending from Nova Scotia to the western half 

 of Europe, is shown by the charts ; on the morning of 

 December 12 the barometer reading on board the 

 Mauretania, in lat. 51° N., long. 21° W., was as low as 

 28-04 inches. A remarkable circumstance connected with 

 several well-developed secondary disturbances which 

 advanced in rapid succession towards Ireland was that 

 none of their centres passed eastward of the Irish Sea. 

 Under their influence, the weather conditions were of an 

 exceedingly unsettled type all through the week. 



The flexure of a rectangular plate under uniform hydro- 

 static pressure is a problem which mathematicians have 

 from time to time attacked by different methods. A new 

 investigation, based on the methods of Mr. Walter Ritz, is 

 now published by Mr. D. Pistriakoff, of the Kieff Poly- 

 technic. It is published in Russian, with a short abstrac: 

 in French. 



Those mathematicians and physicists who experience 

 difficulty in forming a clear mental picture of the concepts 

 of non-Euclidian geometry will find a useful and suggestive 

 paper on the Bolyai-Lobatschewsky system, by Prof. H. S. 

 Carslaw, in the Proceedings of the Edinburgh Mathe- 

 matical Society, xxviii. (1910). The author starts by show- 

 ing how the properties of planes and straight lines in 

 ordinary space can be extended by inversion to spheres 

 and circles through a fi.xed point. He then proceeds to 

 consider the properties of spheres and circles that are 

 orthogonal to a given fixed sphere, and shows that if these 

 be called " ideal planes " and ideal lines, they will be 

 found to possess properties exactly analogous to those of 

 hyperbolic geometry. In the plane geometry thus estab- 

 lished " ideal parallels " are represented by circles which 

 touch on the fixed orthogonal circle, and thus it follows 

 that through a given ideal point two parallels can be 

 drawn to a given line. In short. Prof. Carslaw shows 

 that a geometry identical with that of Bolyai and 

 Lobatschewsky can be built up in ordinary Euclidian space, 

 and, so far as plane gedmetry is concerned, in an ordinary 



