February 29, 191 2] 



NATURE 



599 



Blown away 



Temporary deposit in the town 



Permanent deposit in the town 



Tons. 



'3.472 



48 



35'Ooo 

 The method of determining the permanent deposit was 

 by means of glass plates a foot square, which were ex- 

 posed at different stations for three months at a time. 

 The surface was then rinsed with water to remove any 

 loose material, and the deposit removed and analysed. As 

 tiiis tarry material is much the most deleterious ingredient 

 of the soot, the method of comparing the translucency of 

 these plates after exposure with certain standards may be 

 recommended as a rough test of atmospheric pollution by 

 smoke. 



Cohen and Ruston have calculated that in a domestic 

 fireplace about 6 per cent, of the fuel escapes as soot, 

 whereas in a boiler or other furnace the loss may be 

 reckoned at J to f per cent. Taking the estimated coal 

 consumption from both sources, we get for the whole 

 country a loss in the form of soot of : — 



Tons 

 6 per cent, on the estimated domestic 



consumption of 32 million tons ... 1,920,000 

 0-5 per cent, on the estimated factory 



consumption of 100 million tons ... 500,000 



2,420,000 

 From the ratio of soot emitted to soot deposited in 

 Leeds, the above 2,420,000 tons will yield a deposit of 

 nearly 300,000 tons in the neighbourhood where the coal 

 is consumed ; for it must be remembered that the whole 

 quantity will sooner or later reach the earth. 



Comment is unnecessary. On the ground of the discom- 

 fort, dirt, waste, and pecuniary loss which smoke entails, 

 ) the evil is one which should receive serious consideration, 

 I and it is to be hoped that the forthcoming conference and 

 [ exhibition which is being promoted by the London Coal 

 f Smoke Abatement Society will be successful in directing 

 ' more attention on the part of the authorities to the 

 disastrous effects of smokv chimneys. 



J. B. C. 



T^ 



BELGIAN BOTAMCAI. INVESTIGATIONS.' 

 HE supplementary part of the seventh volume is 

 entirely occupi^-d with a sketch of the geographical 

 botany of Belgium by Dr. J. Massart, providing a con- 

 I tinuation of the more specialised account of the vegeta- 

 j; tion of the littoral and alluvial districts by the same author 

 published in the original volume, and previously noted in 

 Nature. The s]«rtch does not contain any such detailed 

 observations as are recorded in the botanical surveys 

 carried out in Great Britain by W. G. Smith, C. E. 

 Moss, and others, but incorporates the results of various 

 Belgian researches, notably the modification of leaves in 

 dry and moist localities furnished by Miss M. Ernould, 

 the periodic phenomena of vegetation carefully studied by 

 the meteorologist. Dr. E. Vanderlinden, in connection with 

 climatic variations, as well as several geological and agri- 

 cultural investigations. Geology ■ occupies a more 

 prominent position than is usual in an oecologiral botanical 

 memoir, and practically supplies the basis of treatment in 

 the most important chapter. The classification of associa- 

 tions is artificial. Uncultivated and cultivated areas are 

 placed in antithesis. As might be expected in a country 

 where mountain ranges are wanting and intense cultiva- 

 tion is general, there are few natural associations ; apart 

 from the dunes, the most important are the types of vegeta- 

 tion growing on cliffs and rocks. 



A notice of Dr. Massart's able contribution would 

 be quite incomplete without an expression of cordial 

 admiration of the excellent photographs and maps that are 

 collected in the " .Annexe." Of the photographs, more 

 than half are stereoscopic, and to ensure that they shall 



1 "Recueil de I'lnstitut Botinique L^o Errera (University de Bruxelles)." 

 Public par Jean Massart. Tome SuppI6mentaire vii.bis, pp. xii + 332. 

 Annexe ati tome suppltfmentaire vii.bis, pp. iv+466 photographs+g maps 

 + 2 diagrams + pp. v-xiii. Tome viii., pp. ix + 383, avec Stereoscope. 

 (Bruxelles: Henri Lamerton, 1910 and 1911.) 



NO. 2209, VOL. 88] 



be fully appreciated a simple but effective stereoscope is 

 provided. It will be observed that the author has paid 

 particular attention to the photography of cryptogamic 

 plants ; fungi are the most suitable for the purpose, but 

 the lichens (Figs. 434 and 636), the mosses (Figs. 332 and 

 414), and the algae (Fig. 222), also the mycorrhiza of beech 

 (Fig. 320), are particularly well defined. Discrimination 

 between the photographs of flowering plants would be idle 

 where nearly all are successful and convey their special 

 meaning. 



1 he eighth volume contains three extensive papers, a 

 study by Dr. V. Gallemaerts of the phanerogams growing 

 on willows, an investigation by Mrs. J. Schouteden-Wery 

 as to the factors which regulate the distribution of algae 

 off the south-western region of the Belgian shore, and the 

 observations of Dr. Vanderlinden mentioned above ; in the 

 last the observations, concerned chiefly with the com- 

 parative dates of flowering, extend over a period of 

 fourteen years. 



BIOLOGICAL STUDIES IN JAVA.' 

 'PHE memoir referred to below contains a series of 

 articles embodying the results of six months' study 

 and observation in Java in the winter of 1909-10. The 

 subjects dealt with are : — (i) climbing organs within the 

 genus Randia ; (2) Javan Myrmecodia ; (3) the "silver- 

 field " of Haplochilus panchax ; (4) the microbiological 

 processes in the humus of certain humus-collecting 

 Epiphytes ; (5) the bacteria nodules on the leaf-margins of 

 Ardisia crispa. 



Not the least interesting is the account of the author's 

 investigation of the biological phenomena of Myrmecodia 

 tuberosa, of Hydnophyttim montanum, and, incidentally, 

 of Polypodium sinuosum. Miehe briefly reviews the work 

 of his predecessors, Beccari, Treub, and others, on the 

 same subject, and adds a bibliography relating specially 

 to the interrelations of ants and plants. The tuberous- 

 stemmed rubiaceous genera Myrmecodia and Hydnophytum 

 are among the most remarkable vegetable productions of 

 the Malay Archipelago, alike in habit of growth and the 

 econornies of nutrition. These plants are epiphytes, usually 

 gregarious, and commonly associated with the equally 

 singular Polypodium sinuosum. They form irregularly 

 shaped fleshy' stems or tubers, ultimately 6 to 9 inches or 

 more in diameter, with chambers and intersecting or blind 

 galleries, in nature perhaps eventually always inhabited 

 by a certain kind of ant and a fungus. A few short 

 branches bearing a tuft of crowded leaves are given off 

 from the tuberous stem, and the flowers are small and 

 inconspicuous. 



How far the association of these three organisms is an 

 instance of beneficial symbiosis is still uncertain. Beccari, 

 one of the earliest investigators and illustrators of this 

 class of plants, came to the conclusion that the shape and 

 development of the stems was entirely dependent on the 

 action of the ants. But Treub proved by experiments with 

 seedlings and older plants that the development of the 

 thickened stems and the formation of galleries was abso- 

 lutely independent of the ants. Hence some other use had 

 to be sought for the passages and chambers open to 

 exterior influences. Treub and subsequent investigators 

 claim to have proved that these interior surfaces, which 

 are of two kinds, play an important part in the economy 

 of the plant, furnishing, in effect, the channels of absorp- 

 tion and transpiration. The absence of stomata from the 

 exterior parts of the stem and tuber is advanced in support 

 of this theory. 



Miehe instituted further experiments to determine the 

 nature of the vital functions of these two different surfaces 

 of the galleries and chambers. In certain parts of the 

 system the surface of the walls was smooth and of a 

 " leather-yellow," in others black and warted. The 

 result of numerous experiments was the same, namely, 

 that the warty surface rapidly absorbs water, whereas 

 the smooth surface docs not possess this property. The 

 fungus which inhabits the tubers has not been determined, 

 but it is probably allied to Cladosporium and Cladotrichum. 

 1 " Javanische Stiidien." By Hugo Miehe. Pp. 299-431. (Des xxxii. 

 Bandes der Abhandlungen der Mathematisch-Physischen KUsse der 

 Koniglichen Siichsischen Gesells-.haft der Wissenschaften, No. iv.) 

 (Leipzig : B. G. Teubner, tgti.) Price 6 marks. 



