May 26, 192 1] 



NATURE 



413 



to calculate Sutherland's constant (C.=28o) and the 

 viscosity at 0° C. (»?« — o-935x 10-^ C.G.S. units). The 

 mean collision area of the molecule of cyan- 

 ogen deduced, —1-31x10-" cm.', proves to be 

 practically the same as that of a bromine molecule, 

 i-28x 10-'* cm." This is consistent with the evidence 

 from crystal examination, for the molecular volumes 

 of KBr and KCN are nearly equal. If X-ray crystal 

 examination should prove that KCN and KBr are 

 strictly isomorphous, the results here obtained are con- 

 sistent with the Lewis-Langmuir view that the 

 cyanogen molecule has a size and shape nearly the 

 same as those of two nitrogen molecules linked 

 together by sharing one pair of outer electrons. 



Linnean Society, May 5.— Dr. A. Smith Woodward, 

 president, in the chair. — Prof. A. Dendy : Hexactinellid 

 sponges. The origin on certain elongated siliceous 

 spicules of discs at regular intervals corresponds 

 almost exactly with the nodal points of a vibrating 

 body as determined by Prof. J. W. Nicholson. — Six 

 papers dealing with various groups of insects col- 

 lected by the Percy Sladen Trust Expedition : — C. G. 

 Lamb : Diptera (iii.). A report chiefly on the 

 Dolichopodidae, a large family of small- or middle- 

 sized f!ies, usually of beautiful metallic green or 

 golden colours. The general affinities of the Sey- 

 chelles forms are discussed. Most of them belong to 

 a subfamily largely represented in the tropics, the 

 Chrysosomatinag or Psilopinae; some of these flies, 

 with dazzlingly brilliant golden-green bodies, settle 

 in bright sunlight orw broad leaves ; another group of 

 smaller and much duller-coloured species is almost 

 entirely confined to the damp, shady mountain forests. 

 .\ new genus, characterised by the males having at 

 the base of the abdomen a pair of remarkable hollow 

 spherical bulbs, with a round opening at the top 

 through which can be seen a rod rising from the 

 bottom of the bulb, is described. The bases of the 

 wings are also highly modified. The Asilidae and 

 the Syrphidae are also discussed. — H. Gebien : The 

 Tenebrionidae. A large family, mostly of large- or 

 middle-sized beetles. The known Tenebrionid fauna 

 of the island is increased from twelve to fortv-one 

 species ; of these twenty-one are probably endemic, 

 and eleven belong to endemic genera. The endemic 

 genera are isolated and specialised forms. The idea 

 previously advanced by Kolbe, that certain of these 

 peculiar forms indicate relationships between the 

 fauna of the Seychelles and those of New Zealand 

 and South America, is not upheld, for the endemic 

 species which do not belong to endemic genera present 

 Oriental affinities. There is a much less pronounced 

 Madagascan element, while the African element is i 

 represented onlv bv a single widespread form. — Mr. | 

 Schenkling : The Cleridae. A strong aflinity exists 

 with the fauna of Madagascar, four out of the six 

 Seychelles species being new and having strongly 

 Madagascan affinities, while the two remaining 

 species are cosmopolitan. One of the new Seychelles 

 forms has a superficial resemblance to an Anthribid 

 beetle from the same islands. Both belong to new 

 genera, Cleranthribus and Anthriboclerus. There are 

 no data to show relationshio between them. — Dr. M. 

 Bernhauer : The Staphylinid beetles. The known 

 Staphylinid fauna of the Seychelles is increased from 

 twentv-ei^ht to eight>--one species. The report also ' 

 includes one species from the Chagos Islands and 

 two from Aldabra. The conclusions of earlier writers 

 were that the affinities of the Seychelles Staphylinids 

 were, on the whole. Oriental, but that a smaller 

 Madagascan element and a very small African element 

 were included. These conclusions are in the main 

 upheld, but generalisations must be accepted with 



NO. 2691, VOL'. 107] 



reserve, for the smaller forms are still practically un- 

 known in surrounding continents, and it is not known 

 which species have reached the islands by natural 

 means and which through human agency. A sum- 

 mary of observations on habits is given. — Dr. H. 

 Scott : Clavicorn and other beetles. A great deal of 

 fine work on the external anatomy was done in 

 describing these forms. Numerous interesting points 

 in the structure of tarsi, antennae, mouth-parts, etc., 

 and some remarkable secondary sexual characters, 

 came to light. The geographical distribution is shown 

 by a tabulated comparison of the numbers of repre- 

 sentatives of these families in the Seychelles with the 

 faunas of the Hawaian and of the Atlantic islands. 

 The Seychelles have a great number of families and 

 genera, usually represented by a few clearly separable 

 species. The Hawaian islands have several families 

 altogether wanting, while in other groups thev pos- 

 sess great "endemic complexes. "^ — Florence E. Jarvis : 

 The Hydroids of the western Indian Ocean. An 

 account of the collections obtained during the vovage 

 of H.M.S. Sealark at varying depths to 130 fathoms 

 and of some shallow coastal collections made bv Mr. 

 C. Crossland off East Africa. There are eleven 

 Gymnoblastea and seventy-four Calyptoblastea. The 

 number of new species is relatively small, the in- 

 fluence of depth and currents being emphasised as 

 having a marked effect on the habit of colonies. All 

 the larger families are represented, the group being 

 practically cosmopolitan ; there are no new genera, 

 but the species comprise a number of new Plumu- 

 larians.^ — Dr. C. I. van der Horst : Madreporaria, 

 Agariciidae. Twentv-nine species are recorded be- 

 longing to the genera Agaricia, Pavona, Podabacia, 

 Leptoseris, Siderastrea, Coscinaraea, Psammocora, 

 and Pachyseris. The type-specimens of previous 

 authors have generally been consulted. Three species 

 are described as new. The examination of the collection 

 has resulted in many species, previouslv described as 

 different, being shown to be connected bv transitional 

 forms.— E. R. Spever : Insects in relation to the re- 

 production of coniferous trees. The destruction of 

 the cones of Pseudotsu^a Douglasii. Carr., Pinus, 

 honderosa. Dougl., and P. echinata, Mill., bv various 

 insects was discussed. 



Zoological Society, May 10.— Dr. A. Smith Wood- 

 ward, vice-president, in the chair. — R. I. Pocock : 

 The auditory bulla and other cranial characters in 

 the Mustelidae (martens, badgers, etc.). — G. S. 

 Thapar : The venous system of the lizard, Varanus 

 bengalensis, Daud. 



Royal Meteorological Society, Mav 18. Mr. R. H. 



Hooker, president, in the chair. — J. E. Clark 

 and H. B. Adames : Report on the phenologv of the 

 British Isles, December, igig, to November, 1920. 

 The abnormal mildness and wetness up to mid-April 

 ruined fruit-tree crops through too earlv bloomingf. 

 Field crops suffered through drought in May and 

 June and the cold sunlessness of July and August, 

 with excessive wet in the former month. After June, 

 in England, the accumulated temperature above 42° 

 (that at which wheat will grow) fell more and more 

 behind the mean until October, which, by its warmth, 

 sunshine, and dr\-ness, gave a wonderful seeding time 

 in earlier districts and helped to save crops in the 

 later. In 1920 the four spring flowers were, in 

 England and Wales, 13J days early (February 27) ; 

 10 days (March 3) for the whole of the British' Isles. 

 The latter date for 1919 was March 15. The succeed- 

 ing flowers became less and less early, until the two of 

 Julv were just average. From 192 1 on observers are 

 asked to include the Devil 's-bit scabious in order to 



