February 9, 1922] 



NATURE 



191 



of difficulty in consequence of the changing thermal 

 character of the air column between stations at different 

 levels. Perhaps the diurnal variation of pressure 

 affords the best line of approach. A proper formula 

 regularly applied to observations at the top ought 

 to give a diurnal variation of pressure at the base 

 coinparable with that obtained from direct observa- 

 tions at the bottom. What M. Vallot calls the 

 ■classical" method would certainly not do so. There 

 is an interesting paper by Buchan on experiences at 

 Hen Nevis which bears upon the subject. 



Napier Shaw. 



Sponge- Spicules. 



PROF. DENDY'S memoir (in Acta Zoologica, 192 1, 

 pp. 95-152, 50 figures) on the evolution of the 

 tetraxonid sponge-spicule will appeal equally to those 

 interested in problems of evolution or in sponge- 

 spicules from the point of view of form and of their 

 great taxonomic value. It is not only possible to 

 arrange these spicules in an apparently phylogenetic 

 series with a degree of completeness which is perhaps 

 unparalleled in any other group of the animal king- 

 dom, but the structure of the spicule itself, and the 

 different forms which it assumes, are relatively so 

 simple and definite that the problem of accounting 

 for them in terms of physiological or physico-chemical 

 processes seems far more capable of solution than 

 similar problems among the higher animals. Prof. 

 Dendy describes the forms of spicules of the primi- 

 tive Plakinidae, showing that they can all be derived 

 from the tetract, and discusses concisely the evolu- 

 tion of megascleres (tetract, diact, and monact) and 

 microscleres (polyact and diact) and the development 

 of spines leading to the pseudopolyact forms. He 

 also puts forward provisional conclusions as to the 

 development of a spicule. Two kinds of cells — initial 

 cells and silicoblasts — are concerned in spicule forma- 

 tion ; the former cells secrete the organic material 

 (spiculin) which forms the axial thread or proto- 

 rhabd around which the silicoblasts collect and de- 

 posit silica. A growing spicule may come to be com- 

 pletely enveloped by a silicoblast, which has accord- 

 ingly been regarded by nearly all observers as the 

 mother-cell in which the spicule originates. In many 

 cases the number of initial cells increases by cell- 

 division as the spicule grows, and the development of 

 spines and other outgrowths on the primary spicule 

 is effected by the establishment of secondary growing 

 points at the places where spiculin is deposited by 

 initial cells. The causes which determine the form 

 of the spicule are briefly considered, and though some 

 of the characters of spicules are adaptive the vast 

 majority are non-adaptive ; for adaptation in spicule- 

 form, where such exists, no satisfactory explanation 

 seems to be forthcoming. To say that some 

 "instinct" directs an amoeboid silicoblast containing 

 a spicule towards the gemmule or towards the sur- 

 face of a sponge is, as the author remarks, not an 

 explanation. 



Iron Production in India. 



'T'HE Journal of Indian Industries and Labour for 

 A November last (vol. i, part 4) contains, amongst 

 other interesting matter, a summary of the present 

 position of iron production in India which deserves the 

 serious attention of all engaged in iron and steel in- 

 dustries. The large and rapidlv developing coalfields, 

 the enormous deposits of high-grade haematite iron 

 NO. 2728, VOL. I09I 



ore, ample supplies of limestone and of refractory 

 materials, abundant and low-priced labour, all com- 

 bine to place India in the position of a very serious 

 potential competitor in the world's markets. Two 

 firms are producing iron to-day — the Bengal Iron 

 Co., with works at Kulti, on the Barakar River, 

 comprising five blast furnaces, each with an output 

 of 450 tons of pig-iron per twenty-four hours, and 

 the Tata Iron and Steel Works at Jamshedpur, in 

 Singbhum, with three blast furnaces having a capa- 

 city of 900 tons of pig-iron per diem ; the latter firm 

 also possesses a steel works with seven furnaces 

 capable of producing 17,500 tons of ingots per month, 

 whilst extensions to both the blast-furnace plant and 

 the steel works are in course of erection and a plate- 

 mill has just been completed. A number of new 

 works are being projected ; the Indian Iron and Steel 

 Co, is building blast furnaces for an output of 

 600 tons of pig-iron per diem at Hirapur, the Eastern 

 Iron Co. is building blast furnaces close to the Jharia 

 coalfield, whilst the United Steel Corporation of Asia 

 is to establish works producing both iron and steel 

 at Manoharpur ; this last works intends to use coal 

 from the new Karanpura coalfield. The Kirtyanand 

 Iron and Steel Works, near Sitarampur, does not at 

 present propose to make pig-iron, but is confining 

 itself to the production of iron and steel castings. In 

 connection with the Tata works a group of subsidiary 

 concerns have been, and are being, formed at Jam- 

 shedpur to work up the iron and steel produced by 

 these works ; they comprise the Calcutta Monifieth 

 Works (for producing machinery for jute manufac- 

 ture), Enamelled Ironware, Ltd., the Tinplate Co. 

 of India (which will supply the Burma Oil Co. and 

 other Indian oil companies), the Agricultural Imple- 

 ments Co., the Indian Steel Wire Products. Ltd., 

 the Enfield Co., and the Hume Pipe and Con- 

 struction Co. 



University and Educational Intelligence. 



Cambridge. — The governing body of Emmanuel 

 College offers to a research student commencing resi- 

 dence at the college in October next a studentship 

 of the annual value of 150L, which shall be tenable 

 for two years and renewable, but only in exceptional 

 circumstances, for a third year. The studentship 

 will be awarded at the beginning of October, and 

 applications should be sent so as to reach the Master 

 of Emmanuel (the Master's Lodge, Emmanuel Col- 

 lege, Cambridge) not later than September 18. 



The following grants from the Gordon-Wigan Fund 

 are reported : — For plant-breeding experiments, 50/. ; 

 for museum cases, 35?. ; for apparatus for studying 

 marine organisms, 35!. ; for the preparation of rock 

 slices, 20I. ; and for the preparation of sections of 

 fossil plants, loL 



The annual report of the General Board of Studies 

 for the academic year 1920-21 refers to a distinct 

 relief in the congestion in the scientific departments 

 on account of the completion of new buildings. Fresh 

 accommodation for chemistry and engineering has 

 improved the position of affairs in those departments, 

 and is easing it also in other departments. Several 

 laboratories are faced with serious deficits on the 

 year's working, and complaints are made of the 

 effect of the 100 per cent, tax charged on certain 

 things only procurable abroad. Valuable loans are 

 announced of sound-ranging apparatus from the 

 War Office and of radium from the Medical Research 

 Council. 



