474 



NATURE 



[October 5, 191 1 



tion of roads and other works in limestone. It is pointed 

 out that limestone is a dangerous material for public 

 works, owing to the infiltration of water into fissures. In 

 constructing roads and tunnels in limestone or dolomite, it 

 should not be forgotten that these pseudo-compact rocks, 

 owing to the existence of water in fissures and pockets, 

 are especially delicate from the engineering point of view : 

 very slight artificial derangement may have very serious 

 effects on the stability of such a rock mass. — Ph. Negris : 

 The discovery of the Carboniferous and Eocene formations 

 at Mts. Guiona and Vardoussa, west of Parnassus. 



Calcutta. 

 Asiatic Society of Bengal, Seplember 6.— W.Kirkpatrick : 

 Exogamous septs of the Gehara section of Kunchhandiya 

 Kanjars. Whatever the social structure of the primaeval 

 hordes, the system which requires division into exogamous 

 and endogamous septs and sections has taken on a fresh 

 activity under Brahmanical influence. The exogamous 

 septs of the Geharas are mostly of totemic origin, though 

 an exogamous sept is not always totemic ; one can be 

 entirely independent of the other. An exogamous sept may 

 be of local or communal origin, or it may be eponymous, 

 as well as having an occupational origin. In the camp 

 system of " marrying out " practised by the Kanjars and 

 allied tribes of a Gypsy character we are near exogamy in 

 its most primitive form. — Dr. P. T. L. Dodsworth : Some 

 notes relating to the classification, habits, and nidification 

 of the ravens of India. The author maintains that the 

 Panjab raven is distinct enough from the Himalayan 

 raven to be regarded as a distinct species, and should not 

 be united with it into Corvus corax, Linn. Hume recorded 

 it as different in note and in the sheen of the plumage, and 

 Oates noted it as different in the character and shape of 

 the throat hackles. It is a smaller bird. There is a need 

 for extended observations on the Himalayan raven : (i) To 

 what extent does it show a slight seasonal migration ? 

 (2) When does it nest? Mandelli took the eggs in Sikkim 

 on March 5 ; Stoliczka found the bird building on May 4 

 at Aktash, and Walton near Kala Tso Lake in Tibet on 

 April 6. (3) Does it habitually nest on cliffs? and (4) in 

 successive years on the same site? (5) What is the number 

 of eggs? (6) Do both birds share in hatching them? and 

 (7) how long do the young stay in the nest? The author 

 adds some observations on the nidification of the plains 

 raven. Five is the usual number of eggs ; the nest is 

 built, 18 to 24 feet from the ground, of sticks, lined with 

 rags, sheeps' wool, bits of paper, cows' hair, and grass. 

 Various trees are chosen, such as Acacia leucophloea, 

 Dalbergia Sissoo, and Albizzia Lebbek. When feeding 

 these plains ravens are sociable, but in the breeding season 

 they seem to scatter, and probably many cross into 

 Afghanistan. — J. Coggin Brown : Shan and Palung Jew's 

 harps from the Northern States. The Jew's harp used by 

 the Shans and Palungs is distinct from all others in the 

 presence of movable bamboo strips, by means of which 

 the chamber in which the tongue vibrates can be altered 

 and the tone changed in consequence. — R. K. Bhide : New 

 and revised species of Gramineae from Bombay. Diagnosis 

 of the following new grasses : — (1) Danthonia Gammiei, 

 from Castle Rock; (2) Andropogon Paranjpycanum, from 

 Castle Rock ; (3) Enteropogon Badamicum, from Badami ; 

 and (4) Tripogon Roxburghianum, from Badami. Also a 

 note on the identity of Woodroivia diandra, Stapf, with 

 Dimeria diandra, Stapf. — I. H. Burkill and R. S. 

 Fmiow : Corchorus capsularis, var. oocarpus, a new 

 variety of the common jute plant. C. capsularis, var. 

 oocarpus, a variety distinguished by the elongation of its 

 fruit, is a cultivated plant of south-eastern Mymensingh. — 

 I. H. Bur-kill : The polarity of the bulbils of Dioscorea 

 bulbifera, Linn. The bulbils of D. bulbifera are capable 

 of growth from any part of their surface, but they grow 

 most readily from the neighbourhood of the scar by which 

 they were attached to the parent stem. If cut into halves 

 equatorially, both hemispheres may put out shoots, and 

 these shoots appear more readily near the cut than remote 

 from it ; but they appear in a much more restricted way 

 on the abaxillary half (where almost all arise along the 

 edge of the cut) than on the adaxillarv half. — I. H. 

 Burkill : Further spreading of Croton sparsiflorus, Morung. 

 C. sparsiflorus, an alien which obtained an entrance into 

 NO. 2l88. VOL. 87] 



India by Chittagong, it seems, some fifteen to twenty 

 years ago, and about 1905 reached the banks of the 

 Hughli, and before 1907 had reached Gauhati along the 

 Assam-Bengal Railway, has now reached Narayanganj, in 

 a different direction. It has also appeared newly at many 

 stations along the Assam-Bengal Railway. 

 Gottingbn. 



Royal Society of Sciences. —The Nachrichttn (physico- 

 mathematical section), part iii. for 191 1, contains the 

 following memoirs communicated to the society : — 



April 4. — K. Schwarzschild and E. Kron : The dis- 

 tribution of luminosity in the tail of Halley's comet. 



March 24. — K. Stuchtey and A. Wegener : The 

 albedo of the clouds and the earth (measurements made 

 during six balloon voyages). — G. Hamel : Contributions 

 to the problem of turbulent motion. 



May 13. — G. Timminn : Contributions to the thermo- 

 dynamics of equilibria in systems each composed of a 

 single substance, i. 



May 27. — E. Riecke : The theory of Michelson's inter- 

 ference experiment. 



June 17. — K. Wegener: Aerological results for 1910 

 from the Samoa Observatory. — P. Furtwangler : General 

 proof of the partition theorem for Klassenkorper. — O. 

 Milgge : The structure of magnetite and its transforma- 

 tion into specular iron ore. 



July 15.— G? Tammann : Contributions to the thermo- 

 dynamics of equilibria in systems each composed of a 

 single substance, ii. 



CONTENTS. page 



A Zoological Tribute 443 



The Agricultural Development of Egypt. ByE.J. R. 445 

 The Propagation of Electric Currents. By Prof. 



Gisbett Kapp 446 



Marine Refrigeration. By F. H 447 



Radiography. By A. C. J 448 



Our Book Shelf 44S 



Letters to the Editor:— 



Non-Euclidean Geometry.— Dr. D. M. Y. Sommer- 



ville 45° 



Elements of Comet 1911 /".— Prof. J. B. Dale . . 450 

 Rainfall in the Summer of 191 1 and of 1912. — Dr. 



Hugh Robert Mill 45° 



Miniature Rainbows.— Edward A. Martin .... 450 

 The Stone Ages of South Africa. (Illustrated.) By 



Sir H. H.Johnston, G. CM. G., K.C.B 45° 



Californian Trees. (With Diagram.) By W.J. Bean 452 



Imperial Surveying. By H. G. L 453 



France and Classical Education. By A. E. Crawley 454 



Sir Herbert Risley, K.C.I. E 454 



Notes 455 



Our Astronomical Column : — 



Discovery of a Third-magnitude Comet (191 1^) . . 460 



Brooks's Comet, 1911; 4°° 



Quenisset's Comet, 1911/ 46° 



Calcium Vapour in the Solar Atmosphere 46° 



Elements and Designations for Recently Discovered 



Minor Planets . 4"° 



The Masses of Spectroscopic Binaries 460 



Publications of the U.S. Naval Observatory .... 460 



Forthcoming Books of Science . 461 



Two Minor Australian Goldfields and the Antiquity 

 of Man in Australia. By Prof. J. W. Gregory, 



F.R.S 4«4 



Entomological Notes 4*>5 



The Cultivation of Lucidity in Scientific Writings. 



By Dr. H. A. Miers, F.R.S 465 



Some Quantitative Studies in Epidemiology. By 



Sir Ronald Ross, K.C.B , F.R.S. . . . . 466 



Research in Medicine. By Sir Henry T. Butlin, Bart. 468 



Geography at the British Association .... 469 

 Mechanical Science at the British Association. By 



Prof. E. G. Coker . . . 4°9 



Anthropology at the British Association 47 1 



University and Educational Intelligence 472 



Societies and Academies 473 



