594 



NATURE 



[February 29, 191 2 



[huon of South Africa, been compelled to the opinion that 

 I'aspiilutti dilalatum and Phalaris comimilata are the only 

 types which promise to hold their own for more than two 

 yVars in the veldt conditions obtaining in the midlands of 

 Natal ajjainst the competition of native grasses and the 

 weeds of cultivated ground. Paspalum flourishes on very 

 poor soil, and proved excellent for stock. Phalaris is more 

 resistant to frost, but less tolerant of drought and 

 soil poverty. Favourable reports on these grasses are also 

 received from the Transvaal. 



Recknt numbers of the Circular and Agricultural 

 Journal of the Royal Botanic Gardens, Ceylon, deal largely 

 with experiments on the tapping of Hevea rubber, by 

 Messrs. Lock, Bamber, and Holmes. A remarkable pest 

 is also described by Mr. Green. The rubber slug, 

 Mariaella Dussumieri, Gray, frequents recently tapped 

 llevea trees and imbibes the latex oozing from the cuts, 

 thus causing an appreciable diminution of the scrap rubber 

 that could be collected after tapping. It seemed barely 

 ( itdible at the time that any animal could digest liquid 

 rubber, but direct experiment showed that when some of 

 the living slugs were provided with a saucer of rubber- 

 milk they at once began to lap it up. The slugs, further, 

 do serious injury to young plants. The only remedial 

 measures at present suggested are traps and the destruc- 

 tion of all rubbish. 



.■\ I'AiKR has been published in the Journal of the .Asiatic 

 Society of Bengal, by Mr. B. Hooper, on phosphorus in 

 Indian foodstuffs. The author begins by accepting the 

 well-known conclusions of certain medical investigators 

 that the lack of phosphorus in cleaned or milled rice is 

 the predisposing cause of beri-beri. By experimenting on 

 fowls with rice of varying quality, it was demonstrated 

 that polyneuritis (similar to the human disease) was 

 developed when milled, but not husked, rice was used. 

 Rice containing only 0277 per cent, of phosphoric 

 anhydride brought on the disease in a few weeks, while 

 rice containing 0-469 per cent, formed a healthy diet. A 

 number of analyses have therefore been made of rice 

 samples from various parts of India. On an average, un- 

 milled rice contained 0-65 per cent, of phosphoric 

 anhydride, and milled rice 038 per cent. The pulses con- 

 tained more, and it is significant that the pulse-eaters 

 generally remained free from the disease, whilst their 

 neighbours, the rice-eaters, were attacked. 



Not long ago the Secretary of State for the Colonies 

 announced that it had been decided in principle to main- 

 tain the central establishment of the Imperial Department 

 of Agriculture for the West Indies for a further period of 

 ten years. The opportunity has therefore been taken in 

 No. 4 of the West Indian Bulletin to review broadly the 

 work of the Department in the past, and to indicate some 

 of the problems for the future. There are undoubted signs 

 that the West Indies are recovering from the distress in 

 which they have been plunged during the latter part of 

 the nineteenth century. Confidence in the sugar industry 

 has revived as the result of the abolition of bounties and 

 improved trade relations with Canada ; the production of 

 cacao in Trinidad, Grenada, and Jamaica has increased ; 

 a considerable American fruit trade has grown up in 

 Jamaica ; Sea Island cotton has been introduced into St. 

 Vincent, Barbadoes, and the Leeward Islands ; limes have 

 been much grown in Dominica, and rice in British 

 Guiana. But if the conditions are favourable for crops 

 they are equally favourable for pests, and perhaps nowhere 

 is more careful and continuous work necessary on the part 

 of mycologists and entomologists. There is also much 



NO. 2209, VOL. 88] 



scope for the work of the plant-breeder, for it hns lv»<*n 

 shown that some of the new seedling canes are v. 

 more profitable than the older ones. 



Tin; current issue of the Journal of the Quekett Micro- 

 scopical Club (November, 191 1) contains interesting 

 observations, by Mr. D. J. Scourfield, on the use of the 

 centrifuge in pond-life work. He finds that a high speed 

 (7000-10,000 revolutions per minute) is necessary to bring 

 about the concentration of some of the more minute 

 organisms ; when so high a speed is required, centrifuge 

 tubes holding only about 1-5 c.c. are used. This method 

 is to be regarded as accessory to the ordinary methods of 

 collection by means of nets and filters. Mr. C. D. Soar 

 gives a list of fifty species of Hydrachnids (water-mites) 

 collected, for the most part near London, by the late Mr. 

 Saville-Kent, whose account of the anatomy of these 

 animals is also published. Mr. E. M. Nelson contributes 

 some hints on methods of illumination in microscopic 

 work, and lays great stress on the importance of centring 

 the beam of light entering the objective, in order to obtain 

 good definition. Whether the beam is centred properly is 

 most readily ascertained by examining, either with the 

 unaided eye or with a hand-lens, the " Ramsden disc," 

 the centre of which should be illuminated. Mr. Nelson 

 adds some notes on the use of colour-screens. Dr. E. 

 Penard gives an account of fourteen species (three of 

 which are new) of fresh-water Rhizopods from Sierra 

 Leone, and Mr. T. A.. O'Donoghue records the finding of 

 dimorphic spermatozoa in the human flea and in the blow- 

 fly. 



While the geology of Newfoundland has been investi- 

 gated to some extent, its physiography has hardly been 

 touched upon from the modern point of view. In the 

 January number of The American Journal of Science Mr. 

 W. H. Twenhofel contributes a very instructive description 

 of the island from his observations made during a study 

 of the geological structure of the western and north- 

 western coasts. The topography is strongly impressed by 

 the structure, of which the north-easterly trend finds ex- 

 pression in parallel ridges and valleys having the same 

 direction as the folds and faults, softer strata and zones 

 of weakness having been eroded. The upland surface pre- 

 sents the dissected remains of a former peneplain, which 

 once extended over the whole of Newfoundland, and which 

 it is suggested may have been completed before Cretaceous 

 time, like that of the .Appalachian region. Elevated 

 valleys occur at altitudes of 800 to 1200 feet, and may 

 probably be attributed to erosion at a period when the land 

 stood lower by about this amount than at present. This 

 cycle of erosion was not completed, but was interrupted by 

 renewed uplift of the Long Range in pre-glacial times, 

 since the evidence tends to show that this range owes its 

 origin to the faulting upward of a block from the foreland's 

 level. 



The Survey Department of Egypt has commenced the 

 publication of Bulletins dealing with the astronomical and 

 geophysical work carried out at the Khedivial Observatory 

 at Helwan. No. i, by Mr. E. B. H. Wade, deals with 

 the local attraction of the plumb-line in the prime vertical 

 near the Nile Valley, which has been observed during the 

 work on the geodetic survey of Egypt which is in progress. 

 It had been anticipated that so much as 2" might be met 

 with, but when the triangulation had been carried about 

 150 kilometres south of Cairo the values obtained for a 

 pair of azimuths taken to and fro across the valley were 

 found to be discordant to the e.xtent of 11-9'. After the 

 careful elimination of instrumental errors, a direct deter- 

 mination of the difference of longitude between the observa- 



