6cb 



NATURE 



[July 7, 192 1 



segregations. The metamorphic effects appear to be 

 •due to pressure caused by the partial or complete 

 liydration of the anhydrite. 



Edinburgh. 



Royal Society, June 6. — Prof. F. O. Bower, president, 

 ;in the chair.— By request of the council, Lt.-Col. W. 

 Glen Liston gave an address on plague and rats. After 

 a brief historical survey Lt.-Col. Liston traced the 

 course of events by which after the discovery of the 

 bacillus in 1898 the connection between rats and the 

 •disease was established. The link connecting the 

 plague in rats with the plague in men had still, how- 

 ever, to be found. A curious exix-rience of a friend 

 who had been attacked by a swarm of cat fleas on 

 ^entering a part of a house which had been disused for 

 some time suggested the possibility that the rat flea 

 might be the agent of transmission of the disease. 

 Some little time later, in a certain tenement in Bom- 

 "bay, rats began to die from plague, and as the rats 

 tecame scarce, rat fleas began to trouble the in- 

 ihabitants, and cases of plague began to develop among 

 them. Lt.-Col. Liston received a samp'e of thirty 

 fleas caught in these circumstances. Of thes^ fourteen 

 •were rat fleas. Previous experience had shown that 

 out of 246 fleas caught on men, only one was a rat 

 flea. Evidently the rat fleas, deprived of their normal 

 "host, had fastened on man. Another link in the chain 

 of evidence was provided by an outbreak of plague 

 -among some guinea-pigs kept in Victoria Gardens. 

 An examination proved that the guinea-pigs, which 

 normally seldom harbour rat fleas, were infected with 

 many of these, and that plague bacilli were found 

 in the stomachs of some of them. Further experi- 

 TTients were made, and while these were in progress 

 -the Plague Research Commission was appointed by 

 t&n advisory committee of members nominated by the 

 Roval Society of London, the Lister Institute, and the 

 India Office. The findings of this Commission, con- 

 sisting of Major Lamb, Drs. Rowland and Petrie, and 

 T^t.-Col. Liston, have been universally accepted, proving 

 that rats are the chief cause of plague, and that the 

 -plague is transmitted from rat to rat, and from rats 

 ;to men, through the agency of rat fleas. 



June 20. — Prof. F. O. Bower, president, in the 

 ichair.— M. M'C. Fairgrieve : The annual incidence of 

 intelligence and its measurement by the American 

 Army tests. While many boys of high mental ability 

 'have their birthdays in the late spring months, there 

 "is a distinct risk that boys born in these months may 

 prove to have intelligence rather below the normal. 

 This result, previously indicated by an application of 

 the Burt tests to a limited number of boys, has been 

 •confirmed by the application of an American Army 

 test to as large a number of boys as was available. 

 "Norms suitable for the application of the Army tests 

 to other schoolboys are also given, as well as some 

 •evidence that the average intelligence of public-school 

 boys increases up to an age of twenty years rather 

 than the earlier limit of eighteen or sixteen years 

 ^iven elsewhere. — J. M. Wordie : Shackleton Antarctic 

 Expedition, 1914-17 : Geological observations in the 

 "Weddell Sea area, (i) A description is given of the 

 ice-bound nature of Coats Land, where there are 

 250 miles of barrier (shelf-ice) cliffs without bare 

 rocks of any sort. (2) Elephant Island, South Shet- 

 lands, consists of metamorphic schists, striking 

 "N. 70° E. Mr. Tyrrell examined the rocks petro- 

 graphically for comparison with other West Antarctic 

 rocks, but found no resemblances; he considers them 

 to have been in part volcanic ashes originally, but 

 now much silicified and chloritised. (3) South Georgia 

 is given a different interpretation from that of Mr. 

 Ferguson. Exception is taken to his attempt at sub- 



NO. 2697, VOL. 107] 



dividing the rocks and to his interpretation of the 

 structure. Instead of monoclinal folds and block- 

 faulting, one sees extremely complicated folds strik- 

 ing N.W.-S.E. An igneous complex was found at 

 the south-east end of the island. Prof. J. W. Gregory's 

 claim of Palaeozoic rocks is not considered proved, a 

 Mesozoic age for the whole series being regarded as 

 much more likely on the fossil evidence. There is 

 nothing to show that an arc comparable with the Antilles 

 connected the islands of West Antarctica. The neces- 

 sary link, however, between the geologically similar 

 regions of Graham Land and Patagonia may perhaps 

 be found, as Prof. Gregory first suggested, more to 

 the west than South Georgia.— Dr. H. Levy : The 

 criterion for stable flow of a fluid in a uniform, 

 channel. On experimental grounds O. Reynolds 

 found that a simple critical relation exists between 

 the velocity and the size of the channel and the vis- 

 cosity of the fluid flowing along it, which corresponds 

 to the passage from steady to turbulent eddving 

 motion. Aero- and hydro-dynamical experiments 

 during the past few years indicate the existence of 

 such a critical relation in general. Many curious 

 aerodynamic phenomena centre round the explana- 

 tion of this critical state. In the present paper, where 

 the question is regarded from a new point of view, 

 it is shown on general grounds that if a distribution 

 of vorticity is imposed on a viscous fluid, a critical 

 relation should exist between the velocity and size of 

 the boundaries and the strength of the vorticity, 

 separating the stable from the unstable state. The 

 case of a channel along which fluid is flowing with 

 a parabolic distribution in velocity is considered in 

 detail, and the critical relation due to the imposition 

 of a symmetrical pair of vortices deduced and dis- 

 cussed. — Prof. P. Macnair and C. M. Leitch : The 

 genus Clisiophyllum. The representatives of this 

 genus of fossil corals are exceedingly abundant at 

 certain horizons in the Carboniferous rocks of the 

 West of Scotland, especially in that known as 

 the Blackbyre Limestone. These corals were col- 

 lected, sectioned, figured, and described by a Glasgow 

 geologist, James Thomson, who created a very large 

 number of new genera and species. The tvpe-speci- 

 mens were afterwards presented to the Kilmarnock 

 Museum, and were involved in the fire that destroved 

 that institution. The materials studied by the authors 

 include those specimens that were salvaged from the 

 fire and other collections in which the different genera 

 and species had been named by Thomson. These are 

 now in the Kelvingrove Museum, Glasgow. After the 

 examination of several thousand specimens, nine 

 genera and something like eighty species have been 

 included in the genus Clisiophyllum, four variations 

 of which have been suggested round which the genera 

 may be grouped. Eight of these genera were founded 

 on the axial column, and it is on this structure that 

 the four types of variatio.i depend for their signi- 

 ficance. The authors hoped they had shown that 

 these variants are linked together in an ontogenetic 

 sequence, and that this is also a phylogenetic 

 sequence. They believed that the elaboration of 

 species and their supposed values as time-indices, as 

 upheld by the late Dr. Vaughan and his disciples, had 

 been carried to a length wholly unjustified by the 

 available evidence, and urged a return to simpler 

 and more natural methods of stratigraphical and 

 palaeonto'ogical classification. 



Paris. 

 Academy of Sciences, June 13. — M. Georges Lemoine 

 in the chair. — G. Bertrand : Fredholm equations with 

 principal integrals as used by Cauchy. — H. Mineur : 

 Functions admitting a theorem of altrebraic addition. 

 — J. Kampe de Feriet : Hypercylindrical functions. — 



