4o8 



NA TURE 



[February 4, 1909 



may be hoped that our recent political rapprochement with 

 Russia will lead to more study of this important linguistic 

 group, in which much useful work has been done by those 

 scholars whose achievements are recorded by Mr. 

 Marchant. 



In connection with heliotropic sensibility, Dr. P. Froschel 

 contributes to the Sitzungsberichte der kaiserlichen 

 Akademie der Wissenschaft, Vienna (vol. cxvii., part ii.), an 

 account of a preliminary experiment to ascertain the pre- 

 sentation period, i.e. the shortest time for which a light 

 stimulus must be applied to produce a reaction. The 

 presentation period naturally depends upon the intensity of 

 the light. The author finds that the curve expressing the 

 ratio of the intensity to the presentation period talces the 

 form of a rectangular hyperbola. Working with cress 

 seedlings, a discernible curvature was induced in so short 

 a time as two seconds by a light of 200 candle-power. 



A NOTE on the manufacture of ngai camphor from the 

 composite shrub Blumca balsamifera is contributed by 

 Mr. P. Singh to the Indian Forest 

 Records (vol. i., part iii.). This 

 variety of camphor is manufactured by 

 the Chinese, and receives from them 

 its designation " ngai." The investi- 

 gation was prompted by the abundance 

 in certain forest lands of the species 

 noted and Blumea lacera, another 

 species emitting a camphoraceous 

 odour. Ngai camphor would not pro- 

 vide a substitute for the ordinary cam- 

 phor derived from Cintiamomum cam- 

 phora, but has a high value of its own, 

 because the Chinese use it as a medi- 

 cine and for ritualistic purposes, also 

 in the preparation of fine qualities of 

 Chinese ink. 



TliE new catalogue of microscopes 

 and accessories published by Messrs. 

 W. Watson and Sons, High Holborn, 

 gives full details of their extensive 

 series of microscopes, ranging from the 

 " Van Heurck Grand Model," supplied 

 with various ingenious devices for regu- 

 lation, to simple types, low-priced but 

 of guaranteed workmanship, suitable 

 for schools. A new model, the " Standard " is announced, 

 in which the fine adjustment is fi.xed to the side of the 

 limb instead of at the back ; also a new portable instru- 

 ment, that folds up for packing, has been designed. 

 Owing to the success of the new i /6-inch semi-apochro- 

 matic objective with a large working distance, a 1/ 12-inch 

 oil-immersion objective has been computed on similar lines. 

 The museum exhibition microscope and the Porro erecting 

 prism for dissecting work are ingenious novelties. 



In a third part of his studies in root-parasitism, pub- 

 lished in the botanical series (vol. ii.. No. 5) oT the 

 Memoirs of the Department of Agriculture in India, Mr. 

 C. A. Barber deals with the haustoria of Cansjera Rbcedii. 

 Compared with the types Sanlalum album and Olax 

 scandens already described, Cansjera resembles the former, 

 whence the suggestion arises that the genus should be 

 truly assigned to the Santalacese. The small, irregular 

 haustoria are supplied with numerous lenticels and covered 

 with warty excrescences, while the corky tissue forms a 

 characteristic white sheath. Internally the haustorium 

 consists of cortical cells, from which the contents pass 

 NO. 2049, VOL. 79] 



towards the seat of activity, a transitional region where 

 vascular tissue is formed, and a central core, the source 

 of the penetrating and glandular tissue. For the various 

 points of detail in connection with the method of penetra- 

 tion, the development of an endodermis, and other features 

 the reader must refer to the original. 



The fifth part of the fourth volume of the Transactions 

 of the Perthshire Society of Natural Science (1908) con- 

 tains a number of reproductions from photographs illus- 

 trating Mr. H. Coates's presidential address on the glacia- 

 tion of the county. One of these pictures is here given. 

 The activity of the society extends beyond Perthshire, and 

 the Rev. G. Knight writes on the natural history, geology, 

 and antiquities of Duror, Argyllshire, from the mollusca 

 of Loch Linnhe, through " kentallenite, " to Allan Brecl< 

 Stewart, " a soldier of fortune, a spendthrift, and a 

 prodigal." Mr. G. F. Bates describes the igneous rocks 

 of Glen Lednock, the picturesque valley opening north 

 from Comrie ; the successive points in the landscape will 

 be pleasantly recognised by those who have passed over 



• Glen from 

 reproduced i 



Ma 



>howing mounds of fluvio-i;l.'\cial deposits. Photo, 

 's " Scenery and Geology of the Grampians." 



by this route to Loch Tay. Though the paper professedly 

 deals with microscopic details, it is really an account of 

 an excursion, and from this point of view we should like 

 to learn more of the inter-relations of the rocks, especially 

 at their margins, in the field. In an area like this there 

 can be no real distinction between igneous and mcta- 

 niorphic gabbro, such as the author implies on p. 233. 

 Dr. Shand describes crystals of grossularite from Corsie- 

 hill Quarry, including a new hexakisoctahedral form. 

 Dr. Lyell directs the attention of members to the mycclo- 

 zoa to be found near Perth. 



In the Cairo .'Scientific Journal for November, 1908, 

 Captain H. G. Lyons states that the Nile flood of that 

 year was one of especial interest ; the height reached by 

 the river and the volume discharged were above the average 

 for the first time since 1898, although the level was a 

 good deal below the highest recorded at Aswan during 

 the last forty years. This result was due to heavy rain- 

 fall in Abyssinia in July, September, and the early part 

 of October. Captain Lyons considers that one of the most 

 promising lines of attack upon the problem of the 



