578. 



NATURE 



[December 29, 1921 



at increasing heights. On the other hand, Mr. Mal- 

 lory pointed out that descent is definitely an exertion 

 and means growing fatigue even on gentle slopes, and 

 this was particularly noticeable in the case of the 

 coolies, probably because few of them had learned 

 how to husband their strength. Prolonged exertion 

 ac the highest altitude reached, about 23,000 ft., neces- 

 sitated long rest ; this problem will increase the diffi- 

 culty of the last stages. And if anyone fails towards 

 the summit he will require to be sent down with an 

 escort — a contingency which may be likely to occur 

 and will undoubtedly hamper the prospect of success. 

 Mr. Mallory believes that the chances of success for 

 any particular party are small, but that if the attempt 

 were made year after year the summit eventually 

 could be reached. 



The University of Calcutta has published a useful 

 pamphlet, a translation from the Italian of "The 

 First Outlines of a Systematic Anthropology of Asia," 

 by Prof. V. Giuffrida-Ruggeri, of the Royal University 

 of Naples. It gives a useful summary, with references 

 to authorities and statements of physical measure- 

 ments, of the most recent work on this subject. It 

 is a welcome indication of the progress of anthropo- 

 logical studies in India that a work of this kind should 

 be appreciated by the authorities of Calcutta Uni- 

 versity. 



Malacologists will welcome the appearance, after 

 an interval of more than four years, of another part 

 (No. 24) of the " Monograph of the Land and Fresh- 

 water Mollusca of the British Isles," by Mr. J. W. 

 Taylcjr, of Leeds. The first part of this great work, 

 which is probably the most complete account of any 

 faunal group, was published as long ago as 1894, and 

 its progress since the completion of the third volume 

 in 1914 has been much too slow. The present instal- 

 ment contains the beginning of the Xerophila group 

 of the Helicidse, and in text, plain and coloured illus- 

 trations, distribution maps, portraits, etc., is fullv up 

 to the high standard which is characteristic of the 

 w-ork. All who are interested in the mollusca will 

 wish the author more speedy progress with the rest 

 of his undertaking. 



Entomological Bulletin No. 964 issued by the 

 United States Department of Agriculture is devoted 

 to the garden flea-hopper (Halicus citri) and its con- 

 trol. This insect is a striking form belonging to the 

 family Capsidae, and although the male is winged the 

 female is of a different form and generally totally wing- 

 less. Leguminous plants appear to constitute its 

 favourite food, and both the adult and young insects 

 suck the sap from punctures which they make in the 

 tissues. Discoloration and wilting are the symptoms 

 produced, and in severe cases of infestation death 

 supervenes. Clean cultivation in order to prevent the 

 hibernation of the insect in weeds was found to result 

 favourably in reducing the numbers of the pest, and is 

 regarded as the most adequate controlling measure so 

 far devised. 



In a paper of unusual interest in the Journal of 

 Genetics, vol. 11, No. 2, Miss I. Leitch gives an 

 NO. 2722, VOL. 108] 



account of breeding experiments with some of the 

 Princess Beans of Prof. Johannsen. The latter de- 

 scribed a mutation having longer seeds, which arose in 

 one of his pure lines, and bred true, showing it to 

 have been homozygous at the time of its origin. 

 This long mutant (M) has now been crossed with its 

 parent form (E). The seeds from the cross, containing 

 Fj embryos In Fj seed-coats, show curves of distri- 

 bution for length ranging from below the lowest limits 

 of the pure line E to the upper limit of M. Further 

 experiments show that a definite new type, X, shorter 

 and broader than E, is segregated out from this cross. 

 The hybrids either split into M, X, and an inter- 

 mediate type which goes on segregating, or they do 

 not split at all ; and the ratios indicate that a simple 

 Mendelian difTerence is involved between M and E. 

 The mutant type is found to differ not only in length 

 of seed, but also in producing fewer seeds, and in 

 being more liable to fungus attack. It is pointed 

 out that the theory of loss of factors does not 

 account for the nature of this mutation, and it is 

 suggested that the absence of segregation, as de- 

 scribed in certain cases, may have a cytological basis. 



The extensive series of memoirs brought together by 

 Dr. Emil Abderhalden under the title of " Handbuch 

 der biologischen Arbeitsmethoden " includes, as Ab- 

 teilung 10, Heft 2, an illustrated work by O. Abel, 

 of Vienna, on the methods of palaeobiological research 

 (Urban and Schwarzenberg, Berlin, 192 1, 30 marks). 

 The external forms, adapted for special modes of life, 

 exhibited by living animals are freelj' used as aids in 

 restoring fossil remains. Striking examples of con- 

 vergence are also given, where similarity of habit has 

 induced an external similarity which might easily mis- 

 lead where hard parts are alone preserved. Heil- 

 mann's walking Archaeopteryx, compared with the 

 dinosaur Ornitholestes, is interestingly reproduced, 

 but is surpassed by the author's own reconstruction 

 of a pterodactyl on a branch in the attitude of an 

 Indian bat. The appeal throughout is from the fossil 

 to the animate world, and under the influence of these 

 pages we may see Machairodus stealing through our 

 museum corridors, Belemnoids shooting backwards to 

 pierce the entanglement of algae, and Coccosteus elud- 

 ing study by a wave of its long-drawn tail. In 

 Lieferung 28, which forms Heft i of the same Ab- 

 teilung, Th. Arldt, of Radeberg, treats of the methods 

 of palaeogeography. Palaeontology is here called in as 

 an ally, but it must work hand-in-hand with con- 

 siderations of general geology. None of the published 

 palaeographic maps are reproduced, perhaps on account 

 of their lack of resemblance to anything on the earth 

 at the present day. This is, of course, due to our 

 ignorance of topographic details, and the author is 

 modestlv content with a general essay on how to 

 approach a very difficult subject. 



Mr. R. Lloyd Praeger's account of the genus 

 Sedum as found in cultivation, which fills 314 pages 

 of the recent issue of the Journal of the Royal Horti- 

 cultural Society (vol. 46, May, 192 1), will interest the 

 botanist as well as the gardener. The genus is widely 

 spread throughout the northern hemisphere, mainly 



