544 A NEW SMUT ON SORGHUM. 



that infection may not be contined to the scedhng ])lant. but that 

 the fungus may be able to infect the fully-o-rown plant, a.- is the 

 case with several other members of the Gramincce. 



I'^XPI.AXA'IFOX OF PLATI:. 



Photograpii of three inflorescences of . hidropogoii halc- 

 pcvisis Brot.. var. cffiisus Stapf., destroyed l)y smut. Sorospo- 

 riiiiii SI III a Pole l-'^vans. 



J'RAXSACTIOXS OF SOCIETIES. 



Royal Society of South Africa. — Wednesday. April igtli : L. A. 

 Perinouey. D.Sc.. F.E.S.. F.Z.S.. President, in the eliair. — " Xud' on Pfaf- 

 fians connected ivifh tlic diffcrciice-prociuct " : Sir Thomas Muir. 

 Jn addition to the discovery of the connection referred to in the title, a 

 series of theorems was established bringing pfaffians into relation with per- 

 manents and other integral functions. — " Xotc on ihc so-callcd Fahlcn rela- 

 tions bctri,'ccii the minors of a Matrix'': Sir Thomas Muir. The rela- 

 tions in question were critically examined, and an attempt was made to 

 l)ut tlie subject on a sounder Dasis. A rectitication of the statements 

 hitherto accepted re.siardmg tlie history of the s'.ibject was also incidentalli? 

 involved. — " On ii:e de-velofnicnt of the Perlurhaliic Functiin: in the 

 Theory of Planetary Motion " : R. T. A. Innes. The author had pub- 

 lished a paper in tlie Society's Transactions. 191 1. upon the Xewcomb 

 operators used in tlie algebraical development of the elliptic )jerturbative 

 function. A further extension of the uses of tlu^^e Xewcomli operators 

 was dealt with. At best the development of the j^erturbative function is 

 very cumbersome. — "A Contribntion to oar knoivledge of the A'afional 

 Game of Africa " : Dr. P. .\.. "Wagner. Aanong most of the native races 

 of Africa there is ])layed in one form or anotlier, either in row-~ of holes 

 scooped out of the ground or on wood, stone, or e\en ivory hoards, a 

 peculiar game of skill, which from its wide distribution over the continent 

 lias been approjn-iately styled " the national game of Africa." The game 

 was described l)y the author, and is essentially a war game. Two plaj^ers 

 or sides direct a contest between arnu'es of equal strength, the object 

 in view being the capture or "killing" of "men"" who are represented 

 by small stones, seeds, shells or fragments of dry cow dung. — '' A Snrz-cy 

 of the Scorpion fauna of South Afriea " : J. Hewitt. The main features 

 of the Scorpion fauna of South Africa have been known for some years, 

 though up to the present no complete lists or descri])tions of the fauna as 

 a whole have been available. The author sought to provide a reliable 

 synopsis of the main distinguishing characters of all the species and varie- 

 ties known to inhabit South .\lrica. — "Xote on a petiole and portion of the 

 lamina 0/ Cotyledon orhlcuhAa. function: n(^ as a stem" : Prof. S. Schonland. 

 The author described a case of the formation of adventitious roots on a 

 leaf of Cotyledon orbicuhita. which remained attached to its stem for seven 

 months afterwards. The roots grew considerably, the petiole and the 

 lower part of the leaf thickening and resembling the stem in outward 

 appearance. The petiole retained the external structure of such an 

 organ, and did not turn into a stem, although it had to perform stem- 

 functions for a long time, hi analogous cases in other plants, radical 

 changes have been observed. 



South Afkuan Ix.stitutf of Electrical Exctneers. — Thursday. 

 April 20th : Prof. W. Buchanan. M.T.EE.. President, in the chair. — "A 

 iiezi.' system of mine signalling " : R. H. Gould. [Mine signalling is usually 

 effected by means of trembling bells worked off a D.C. supply. The 

 system described by the author embodies the advantages of the single- 

 stroke bell system, while also preserving the advantages of trembling bells. 

 The connections used underground are identical with those now useil for 

 tremliling bells : the surface outfit is readily mounted on a switchboard, 

 pu 1 there are onlv two vibrating contacts in the whole system, these 

 being on the surface and easily inspected. 



