December 9, 1920] 



NATURE 



489 



The minimum lethal dose of cobra venom for the cat 

 is twenty times that for the rabbit (by subcutaneous 

 injection per kg.), (b) Acquired Immuniiy. — When a 

 rabbit is immunised to cobra venom the isolated heart 

 and intestine, perfused with Locke's solution so as to 

 remove the serum, withstand higher concentrations 

 '.f venom than the heart or intestine of a normal un- 

 inmunised rabbit. — L. T. Hogben : Studies on 

 \napsis. III. : The nuclear organisation of the 

 :(Tm cells in IJbellula depressa. (a) The nuclear 

 organisation of the germ cells in IJbellula depre:isa 

 i-i investigaltnl with a view to further knowledge of 

 (i) relation of kinetic processes in premeiotic and 

 ineiotic phases, and (ii) bearing of nuclear emission 

 in oocyte upon integrity of chromosome complex in 

 meiotic phase, {b) In the premeiotic telophase the 

 chromosomes spin out into finely granular loops, dis- 

 playing initially a polar disposition, becoming in- 

 creasingly more attenuated in the spirophase, and fiist 

 recognisable individually in the prophase at attenuated 

 ( onvoluted fdaments. (c) The Leplotene bouquet is 

 regarded as owing its character to the polarisation of 

 the normal telophase. (d) The behaviour of the 

 "double nucleolus" has been thoroughly studied; the 

 ((l.ismosome is independent of the chromatin organisa- 

 tion of the nucleus. 



Zoological Society, November i6.— Prof. J. P. Hill, 

 vice-president, in the chair. — Dr. W. A. Cnnnlngton : 

 Fauna of the .Xfric.-m lakes, with special reference 

 to Tanganyika. .After referring to certain physical 

 and geological features which have a bearing on the 

 subject, the nature of the various animal forms In- 

 h.ibiting the lakes was dealt with. Tanganyika was 

 •-hown to have a very distinctive fauna, in that (i) it 

 inrlu<les many more different types than any of the 

 iilher lakes, (2) an e.xtremely large proportion of them 

 ,ire not fourid elsewhere, and (3) certain forms 

 (notably (iasleropoda) are considered to have a 

 marine-like appearance. The view previously put 

 forward which regarded the lake as the remains of 

 an old Jurassic sea was considered untenable, since 

 many of the types thought to be marine an<l primi- 

 tive belong to essentially fresh-water groups and 

 ••liow signs of specialisation. The Jurassic hypo- 

 thesis proves likewise incompatible with recent geo- 

 logical evidence. .After discussing various other 

 theories, it was suggeste<I that Tanganvika probablv 

 owes its remark.al)le organisms to a prolonged peritxl 

 of isolation, coupled, tirrhaps, with the effect of an 

 increa.sed salinitv which isolation would involve. — 

 H. F. Carter : l)escrii>lions of the adult, larval, and 

 ipal stages of a new mosquito from Lord Howe 

 land, .South Pacific- Prof. C L. Boalenger : Filariid 

 nrms from mammalia and binL ;n il^- society'.s 

 irdens, t()i4 15. 



IniDtution ol .Mining and Metallurgy, November iS. - 

 Mr. I'raiik .\I(■rrick^, president, in the chair, -f. 

 Brackenbury : .An automatic counting machine for 

 checking tram-wagons. At a quarry in which the 

 workmen were paid on piecework, their wages 

 depending chiefly on the numt)er of wagons of 

 material sent to the dump and over the weighl)ri<lge, 

 the author devised a simple scheme for registering 

 each wagon as it |)asse<l up the ini line. The up- 

 line was provided with catch-rails for the purpoiw of 

 derailing nmaway wagons, and as each wagon 

 paK<ied the open switi h the whiel-flanges moved the 

 rail. .Suitable levers and wires connected the switch 

 with an automatic counting machine situ.-ited in the 

 office, with the result that every complete movement 

 of the switch-rail registered a new unit on the coimter. 

 In this manner both tl)e management and the work- 

 men were satisfied that a correct record of the move, 

 .mcntu of the tram-wagons could be kept. — II. C. 



NO. 2667, VOL. 106] 



Robson : Converting high-grade matte in magnesite- 

 lined converters. This paper contains a record of 

 work done at the Spassky Copper .Mine, Siberia, 

 where in 1915 two lo-ft. "Great Falls" magnesite- 

 lined converters were installed in place of three 5-ft. 

 acid-lined converters. From the start the new con- 

 verters were run with the idea of keeping a protective 

 coating of magnesite on the brick lining. This was 

 effected by blowing to white metal a 5-ton charge of 

 matte with flux, followed by a similar amount without 

 flux and li tons of cold matte, the whole being blown 

 to blister-copper. One of the chief difficulties in con- 

 verting high-grade matte is keeping the tuyeres open, 

 especially with slags high in iron and low in silica. 

 From his e.xperience the author can see no reason 

 why any commercial grade of matte should not be 

 treated if correct working conditions be maintained ; 

 with matte assaying between 55 and 60 per cent, of 

 copper it was not possible to produce a slag con- 

 taining less than 6 per cent, of copper. -A blister- 

 copper assaying about 98-8 per cent, of copper with 

 a small percentage of sulphur was always produce<l ; 

 attempts to produce copper of a higher grade caused 

 difficulties by the coolinc of the charge. The paper 

 contains tables showing respectively the operating 

 data of the converters, analyses of the converter pro- 

 ducts and by-prcHlucts, and particulars of the operating 

 temperatures in three trial charges. 



LInnean' Society, November 18. — Dr. .A. Smith 

 W'fMxKvard, president, in the chair. — Prof. E. S. 

 (joodrich : .A new tvpe of teleostean cartilaginous 

 pectoral girdle found in young Clupeids. In the 

 young of Clupea spratlus, C. harangus, and C. pil- 

 ihardui, about 20-30 mm. in length, the right and 

 left coracoid regions fuse to a solid cartilaginous 

 ventral bar. which becomes bent and again sub- 

 divides in later stages. This fusion is probably .1 

 specialisation to strengthen the support of the pec- 

 toral fins before the complete developinent of the 

 dermal bones of the pectoral girdle.— Dr. J. C.' 

 WilUi : Emlemic genera in relation to others. In 

 a paper of 1916 the deduction was made that_ in 

 general endemic species of small area were not relics, 

 but species in the early stages of spreading, and 

 much evidence has since l)een brought up to show 

 the truth of this. It is now proposed to extend this 

 deduction to endemic genera, and to endeavour to 

 show that there is no appreciable difference between 

 a local endemic and an allied genus of wide dis- 

 tribution (of course, working alwavs with groups of 

 genera) oth-r than age. The author has added up 

 all the endemic genera of all the islands in the. 

 world, and for romoarison also those of (i) West 

 Australia. South Africa, and Brazil (the mainl.ind 

 areas richest in endeinics) ; (u) of .Australia, .Africa, 

 and South Am-rjca : and <\) of the world. F.xamina- 

 tion of the tables thus obtained soon shows that if 

 one takes the families in croups of ten in order 

 accordini' to the number of ftenera thev contain in 

 the world (i.e. heuinnin" with Composilip and_ end- 

 ing with monotvnic fpmilies). the r>roportion of island 

 cenera to the total is r|os-lv the same throughout 

 the list, and the same holds for all the (our are.ns 

 mentioned. Thus the first ten families contain 

 4CV.I per cent, of the cener.i of the world, 3<v-< per 

 rent, of those of .Australia, Africa, and South 

 .America, 405 oer rent, of those of W'esf .Aus- 

 tralia, etc.. and ^8 1 per rent. (606 genera out of 

 1 582) of the endemic Cenera of islands. .And the 

 .•inproximation is equallv close all down the scale, 

 so ihat the curves nr<Kli"e<l almost coincide. Com- 

 mrison shows with eoual clearness that the propor- 

 tional renresrntation amomr the eixlemic trener.'' of 

 islnntls derre.ises as one t'oes down the scale. The 



