2»6 



NATURE 



[May 6, 1909 



Bernheim records, in the Bulletin of the Johns Hopkins 

 Hospital for April (xx., No. 217), some experiments per- 



• formed on dogs in this connection ; the results are 

 encouraging, and suggest that the procedure offers no 

 greater technical difficulties than numbers of others which 

 are in daily practice. 



In a report by Mr. E. H. Ross on the prevention of 

 fever on the Suez Canal (Cairo: National Printing Depart- 

 ment, 1909), mosquito destruction at Port Said and its 

 results are reviewed. After three years' work a great 

 reduction in the number of mosquitoes has been effected, 

 and in consequence malaria has much diminished, also 



■ continued fever and dengue. Although the population is 

 increasing steadily, the death-rate for 1908 is 150 below 



' the average for the previous five years. It is not possible 

 completely to exterminate mosquitoes, and the campaign 

 has to be continued. In an appendix certain interesting 



■ features in the biology of mosquitoes (CuXex fatigans and 

 Stegoniyia fasciata) are detailed. It is found that male 

 mosquitoes do not live more than a few days, and are 

 much more numerous than females. The females appar- 



• ently desire to suck blood only after fertilisation. 



In a third report on research work, Dr. Houston, 

 director of . water examinations. Metropolitan Water 

 Board, discusses the value of the storage of raw river 

 water antecedent to filtration as a means of purification. 

 The medical advisers of the Local Government Board have 

 long held the view that " time " is to be regarded as an 

 important element among conditions that in nature com- 



■ bine to annul the vital activities of particulate matter 

 which is the cause of disease, and in no direction perhaps 

 is this " time factor " of more importance than in the 

 storage of impure river water. The results of a large 

 amount of experimental work, chemical and bacterio- 

 logical, undertaken to investigate this question are given 

 in this report. They show that the total number of micro- 

 organisms and of B. colt are very considerably reduced 

 by storage. The stored waters also contained less 

 ammoniacal nitrogen and less oxidised nitrogen, and 

 absorbed less oxygen from permanganate ; as regards 

 albuminoid ammonia, however, only Chelsea water showed 

 a reduction ; Lee water was unaltered, and Staines and 

 Lambeth suffered an apparent increase. The engineers 

 reported that the use of stored water prolongs the life of 

 the filter-beds. It is concluded that an adequately stored 

 water is to be regarded as a " safe " water, and its use 

 would render any accidental breakdown in the filtering 

 arrangements much less serious than otherwise might be 

 the case. Although it would be preferable to regard thirty 

 days as a minimum period of storage, this would entail 

 the construction of huge reservoirs, and it is suggested 

 that thirty days' storage might be considered a maximum, 

 adopting in addition, during times of stress and storm, an 

 intermediate system of purification {e.g. by mechanical 

 filters or by precipitation tanks) between storage and sand 



■ filtration. 



A SECOND part of the illustrated studies in the genus 

 Opuntia, by Mr. D. Griffiths, has been received, being an 

 advance publication from the twentieth annual report of 

 the Missouri Botanical Garden. It consists chiefly of 

 descriptions of new species from the States of Mexico, 

 Texas, and Arizona, with illustrations to indicate the 

 general habit, fruits, and seeds. 



An article by Mr. E. Maigre on geotropism and the 



statolith theory appears in the Revue ginirale des Sciences 



(March 15). Discussing the much-debated question as to 



: the exact position at which the root is sensitive to gco- 



NO. 2062, VOL. 80] 



tropic stimulus, the author lays stress on Picard's experi- 

 ment, in which the root was rotated round an axis oblique 

 to the longitudinal axis of the root. The root was placed 

 in different experiments so that the axis of rotation cut 

 it at different points between the tip and region of growth, 

 and thereby the stimulus produced by centrifugal force 

 acted oppositely on the two regions. The author defends 

 the statolith theory mainly on the strength of Buder's 

 recent researches, wliich consisted in turning the root 

 sharply through an angle of 180° at stated intervals, when 

 it was found that the curvatures produced were in con- 

 formity with the theory. 



Mr. E. D. Merrill contributes three articles to the 

 botanical number of the Philippine Joitrnal of Science 

 (vol. iii.. No. 6) published in December, 1908. A revision 

 of native species of Garcinia shows seventeen species, of 

 which twelve are endemic and five are new to science. 

 The indigenous Ericacese are collated under the genera 

 \^accinium, with nineteen species, Gaultheria, Diplycosia, 

 and Rhododendron, with sixteen species ; all are plants 

 growing at medium or high altitudes, and according to 

 existing records, out of thirty-nine species as many as 

 thirty-six are endemic. The third contribution relates to 

 collections of plants from the Batanes and .Babuyanes 

 islands, which furnish evidence of a strong affinity with 

 the flora of the other Philippine islands and a very slight 

 affinity with the flora of Formosa. There is also a note- 

 worthy communication to the journal by Dr. E. B. Cope- 

 land regarding new genera and species of Bornean ferns. 

 The new genera are Macroglossum, a marattiaceous fern, 

 and Phanerosorus, the latter being, however, a new title 

 for Matonia sarmentosa. 



The reports on the botanic station, agricultural instruc- 

 tion, and experiment plots at Grenada are to hand. The 

 chief industries of the island are cacao and nutmeg cultiva- 

 tion, but it is suggested that fodder crops and ground 

 provisions might with advantage be more extensively 

 grown. Interest is being taken in rubber planting ; Hevea 

 brasiliensis appears to be more promising than Castilloa 

 elastica. It has been demonstrated that Sea Island cotton 

 can be produced on land near the coast. The importance 

 of improved methods of cultivation and treatment in cacao 

 orchards has been continuously urged upon growers, and 

 both large and small owners are adopting such methods. 

 Prize-holdings competitions have been introduced among 

 the peasantry, and have been found to encourage better 

 methods of working. 



Mycologists will be interested in the regulations drawn 

 up by the Board of Agriculture of British Guiana, and 

 recorded in the Agricultural News for March 20, dealing 

 with the importation of sugar-canes, and having for their 

 object the exclusion of plant diseases so far as is possible. 

 Canes from stated places must not be imported in any 

 description of earth or soil. They are to be inspected on 

 arrival by the Government botanist, and if infected with 

 any pest or disease not commonly known in the colony 

 they are to be destroyed ; if infected with any common 

 pest or .disease they are to be treated as the botanist 

 directs. Those passed by the botanist are to be planted 

 in a nursery apart from the general cultivation, and sub- 

 ject to inspection for twelve months ; if during that time 

 any pest or disease appears, they are to be destroyed 

 if the pest is new, or treated as the botanist directs should 

 it already occur in the colony. The regulations are very 

 stringent, but the introduction of new pests and diseases 

 is a very serious matter to agriculturists, and entails a 

 great amount of trouble besides considerable financial loss. 



