770 



NATURE 



[February io, 192 i 



Kemp was the artist he should have included a scale. 

 Among the many figures in this part of the Records 

 the magnification is given in only four cases. 



In the Proceedings of the United States National 

 Museum (vol. Iviii., No. 2344) Messrs. C. P. Alexander 

 and W. L. McAtie deal with the crane-flies and their 

 allies (Tipuloidea) found in the District of Columbia. 

 These insects are prevalent in almost all parts of 

 the world, and they are restricted only by intense cold 

 and dryness. Water or moisture is a necessary condi- 

 tion for the development of most species, and, con- 

 sequently, deserts form efficient barriers to their dis- 

 persal. Among the more interesting features in this 

 paper is a note on the occurrence of the rare and 

 primitive insect Protoplasa Fitchii; several larvae 

 which are referred to this species were found in a 

 decayed drift log, but the adults were not bred out. 

 The winter-gnats (Trichocera) are represented by 

 three species, and the authors follow other recent 

 writers in referring this genus to the Rhyphidse. 

 The greater part of the paper is devoted to the rich 

 fauna belonging to the family Tipulidae, which is 

 represented by 40 genera and more than 190 species. 

 The authors include notes on the larval habits of all 

 species wherever known, and they append useful 

 synoptic keys to the various groups along with their 

 genera and species. 



Profs. A. C. Seward and B. Sahni have contri- 

 buted to the Palaeontologia Indica (vol. vii., Mem. i, 

 in Memoirs of the Geological Survey of India, 1920) 

 a memoir entitled " Indian Gondwana Plants : A 

 Revision." The specimens were mostly among those 

 described by Feistmantel, but a revision of the species 

 in the light of modern knowledge had become neces- 

 sary. The memoir is illustrated by seven fine folio 

 plates, partly photographic, partly from drawings by 

 Mr. T. A. Brock, as well as by a few figures in the 

 text. The senior author was helped in the early 

 stages of his work by Miss Ruth Holden, a young 

 ."Xmerican botanist, whose premature death while on 

 medical service in Russia is a grave loss to science. 

 Prof. Sahni came in at a later period, and hopes to 

 continue work on the same lines in his own country. 

 Two quite distinct floras are dealt with : the Lower 

 Gondwana, of Permo-Carboniferous age, and the 

 Upper Gondwana, which is Jurassic. As regards the 

 former, the authors point out that their results sug-- 

 gest a closer resemblance between the Indian plants 

 and their contemporaries in Europe and North 

 -America than had hitherto been realised. For 

 example, the Gondwana genus Noeggerathiopsis is 

 now merged in the familiar Cordaites. The speci- 

 mens from the Upper Gondwana include several 

 good examples of Williamsonia fructifications, very 

 similar to the well-known European fossils, and to 

 those from Mexico recently described by Dr. Wie- 

 land. This illustrates the author's conclusion that 

 the examination of the Indian Jurassic species has 

 revealed additional evidence of the remarkable uni- 

 formity of Jurassic floras of widely separated regions. 

 The specimens described in the memoir are impres- 

 sions, not petrifactions showing the structure, but 



NO. 2676, VOL. 106] 



use has frequently been made of modern methods to 

 bring out such microscopic details, i.e. of the epi- 

 dermis, as can be recognised. 



The Archives of the Cambridge University Forestry 

 Association (No. 4, October, 1920) contains an illus- 

 trated article by Mr. H. Stone on the origin of the 

 so-called medullary rays in wood. This paper, which 

 advocates a new theory, contains some information 

 about bird's-eye maple and the cause and nature of 

 the pith-flecks which are so characteristic of birch 

 and certain other woods. The author also discusses 

 the capricious occurrence in the natural orders and 

 in allied genera of the broad compound rays which 

 give rise to "figure " in oak, beech, and plane. 



The Queensland Geological Survey Publication 

 No. 267 (1920) is a description of petrified plant re- 

 mains from the Queensland Mesozoic and Tertiary 

 formations, by Prof. Birbal Sahni. The series in- 

 cludes two ferns belonging to the genus Osmundites 

 which were previously known only from Jurassic rocks 

 in New Zealand ; seven species of gymnospermous 

 woods, six of which are described as new ; and three 

 species of angiospermous woods, two of which are 

 new. 



The Norwegian Meteorological Institute has pub- 

 lished its Jahrbuch for 1919, containing records of 

 the observations of more than seventy stations. 

 Hourly records are given for Kristiania and Aas, daily 

 means for twelve stations between Mandal in the 

 south and Vardo in the north, and monthly means 

 for the other stations. An appendix gives the 

 observations at Green Harbour, Spitsbergen, for 

 the year 1918-19. The institute has also published 

 " Nedboriagttagelser i Norge, " giving the precipita- 

 tion records for igig for 491 stations and a large- 

 scale coloured map showing the distribution of the 

 year's precipitation. 



Dr. Murray Stuart's final report on the Srimangal 

 earthquake of July 8, 1918, is published in the last 

 part of the Memoirs of the Geological Survey of India 

 (vol. xlvi., 1920, pp. 1-70), the principal results having 

 been already given in a preliminary report (see 

 Nature for April 3, 1919, p. 91). The new memoir 

 contains full details of the nature of the shock and 

 the damage to property, a discussion of the seismo- 

 grams at distant observatories, and an account of the 

 changes of level in the central district. The epicentre 

 is situated in the Balisera Valley, 3^ miles south of 

 Srimangal railway station, and the epicentral area 

 (the longer axis of which is directed about west-north- 

 west) is crossed centrally at right angles by the line 

 of levels made in 1911-12 from Silchar to Comilla. 

 During the winter of 1919-20 the levelling along this 

 line was repeated by the trigonometrical survey, and 

 this shows that in the interval no settlement had 

 taken place on the north-east side of the epicentral 

 axis. Nor is there any evidence of disturbance on the 

 other side of the axis until the low range of hills six 

 miles west of Srimangal is crossed, but from this 

 range to a distance of thirty miles from the town a 

 subsidence of from ij in. to 9 in. has occurred. It 

 would thus seem that " the earthquake was due to 



