February 12, 1920] 



NATURE 



649 



take place after Easter. The appointment will be 

 for five years, and the value of the fellowship is 

 approximately 500/. per annum. The person elected 

 will be expected to pursue his investigations at the 

 I'niversitv of Sheffield, if possible. .A, copy of the 

 regulations governing the fellowship is obtainable 

 from the Royal Society, the secretaries of which will 

 receive applications for the fellowship itself up to 

 April 20. 



A COURSE of five public lectures is to be given at 

 ; o'clock on successive Wednesdays, beginning on 

 February 25, at the Imperial College of Science and 

 Technology, South Kensington, by Sir Richard Glaze- 

 brook, the University of London Zaharoff professor 

 of aviation. The subjects will be: — "Aeronautical 

 Research," "Stability and its Investigation," "Instru- 

 ments and Methods of Full Scale Research," " Strength 

 of Construction." and "The Airscrew: Its Design 

 and Efficiency." Application for tickets of admis- 

 sion should be made to the Registrar of the college. 



SOCIETIES AND ACADEMIES. 

 London. 

 Royal Society, January 29. — Sir J. J. Thomson, 

 president, in the chair. — Prof. W. Bateson and Caroline 

 Pellew : The genetics of "rogues" among culinary 

 peas (I'isum sativum). In a previous communication 

 (Proc. R.S., Ixxxix., 1915) the authors showed that 

 certain intermediates between types and rogues in 

 peas had a peculiar genetic behaviour. Families 

 raised by self-fertilisation from them consist of a small 

 minority of type-like plants and a majority of 

 rogues. Preliminary experiment showed that the 

 type-like plants come from seeds contained in the 

 lower pods. Investigations of the past four years, 

 consisting chiefly of reciprocal crosses made from suc- 

 cessive flowers, have confirmed this conclusion, and 

 proved further that the ratio of type-like to rogue- 

 like gametes is different on the female and male sides. 

 On the female side the ratio is about equal for the 

 lirst ten flowers, after which the proportion of 

 rogues increases. On the male side, taking the 

 tyjie-Iike gametes as unity, the proportion of rogue- 

 like for the first six flowers in succession is as 

 follows : — 46, 49, 7, 10, 12-3, and 29-5. From self- 

 fertilisations the proportion found for the first six 

 flowers is 15, 11, 13, i:;, 54, and more than 100. 

 There is thus a gradational change in successive 

 flowers. This gradual elision of the type-characters 

 must be brought about by a process similar to that 

 which operates more rapidly in the case of V, plants 

 bred bet\veen type and rogue. These, though con- 

 taining the type, bree<l rogues only, the type being 

 excluded in the base of the plant. — L. T. Hogben : 

 Studies of synapsis. I. : Oogenesis in the Hymeno- 

 ptera. The more salient conclusions arrived at are 

 as follows : — (i) Sex determination in 9 acamically 

 produced : In Cynips and Rhodites (apamic forms) 

 there is reduction of the chromosomes in the young 

 oocyte. The somatic number of chromosomes in 

 Rhodites is 18, as believed by Henkinc The chromo- 

 somes of the younp- oocyte counted by Schleip are 

 double (bivalent). Henking's belief in the doubling 

 of chromosomes in segmentation is confirmed. Roth 

 nolar bodies are probably formed as the result of 

 homotypic division. (2) The maturation iironhases : 

 .\ dlnloteric and pachvteric stage with the bicinlo'd 

 number of filaments follows synapsis in all cases in 

 the voung oocyte. .At this stai?e nurse-cells are dif- 

 ferentiated. In Cvnips, Rhodites, and Orthooelma 

 the diploid number reappears after a "diffuse" stage. 

 These univalents pair end to end, as described b\ 

 Heynes in Conidcsoma. There are thus two chromo- 



NO. 2624, VOL. TO4] 



some conjugations in the parasitic Hymenoptera, as 

 described in Lepidosiren by .\gar, but not hitherto 

 confirmed in other animals by other work. An abor- 

 tive spindle followed by an atypical formation of polar 

 bodies appears to be general in the Hymenoptera. 

 (3) Secondary nuclei and the oosoma : Secondary 

 nuclei were observed in the oogenesis of Syncrgus, 

 Formica, and Lasius. They appear to arise from 

 chromidia ejected from the germinal vesicle at the 

 time when the latter undergoes diminished staining 

 capacity. The "oosoma" arises in Synergus as a 

 cloud of cytoplasmic granules. It is not nuclear in 

 origin. — H. Onslow ; A periodic structure in many 

 insect scales, and the cause of their iridescent colours. 

 The cause of iridescence in insects, etc., still remains 

 unexplained. The minute structure of many iridescent 

 bodies was investigated, because the most eminent 

 physical authorities differed fundamentally as to the 

 cause of their colour. The great variety of structures 

 described and illustrated shows that each obiect must 

 be iudged on its own merits, because no general theory 

 will explain all cases. The princioal type of colour- 

 nroducing structure found in butterflies has not 

 h'therto been described. It consists of transparent 

 plates of chitin separated bv films of air. These olates 

 are at right angles to the scale-surface, and only 

 a few half-wTve-lengths in thickness. Their heighf. 

 shape, and colour together control the colour-tone and 

 saturation. Some butterflies have plates of chitin ap- 

 parently parallel to the plane of the wing; others, 

 again, show structures the colour of which cannot be 

 explained. Reasons are given showing that the mono- 

 chromatic transmission and reflection colours in 

 beetles' scales are probably not entirely due to 

 "gratings," as was proposed by Michelson. The chief 

 objections to metallic reflection in the case of scales 

 are not met with in the wings of scaleless beetles. 

 Here the colour-producing layer is so near the surface 

 that it would be difficult for any other adequate struc- 

 ture to exist. In certain beetles the colour is pro- 

 duced by a thick layer of doubly refractive rods, such 

 that sections tangential to the surface still retain their 

 colour. The wing chitin of golden "tortoise beetles" 

 appears metallic at all depths when moistened, but 

 loses colour when dry. In other insects and some 

 ticks the colour returns on wetting, apparently because 

 there is a thin film, which by adsorbing water becomes 

 transparent, and can cause interference. Iridescence 

 in dragon-flies, the eves of flies, plants, and certain 

 hairs, such as the golden mole, is also discussed. 



Mineralogical Society, January 20. — Dr. A. E. H. 

 Tutton, past president, in the chair. — Dr. E. S. 

 Simpson : Gearksutite at Gingin, Western .Australia. 

 This mineral, which occurs in Cretaceous greensand, 

 is considered to have a composition corresponding to 

 the formul.i CaF,.AlF(OH),.H.O, and to have 

 originated from the interaction in situ of fluorapatite, 

 gibbsite, and carbonated water.— C. E. Barrs : Fibro- 

 ferrite from Cvpnis. Analysis of material from 

 Skouriotissa, ("yprus, g.ive the following result . 

 Fe,0,, 31-36; SO,, 3095; HjO (by dilTerence), 3701; 

 insolubfe, o-68.— Dr. G. T. Prior :' The classification 

 of meteorites. For purposes of the classification of 

 meteorites, the significance is pointed out of the 

 chemical composition of the nickel-iron and the 

 rjiagnesium silicates. In the case of meteoric irons, 

 the structural features, as revealed by etching, are 

 shown to be closely related to the content of nickel. 

 In meteoric stones the proportion of magnesia to 

 ferrous oxide in the magnesium silicates varies 

 ! directly with the proportion of iron to nickel in the 

 ] nickel-iron. On these principles the four classes of 

 ' meteorites, viz. irons, stony-irons, chondrites, and 

 > achondrites, can be divided into interrelated groups. 



