The price of this Journal to the general public is as marked on the front 

 page. Everj^ member of the Association is supplied with one copy free, and 

 may obtain extra copies at half-price. Applications for copies should be 

 addressed to the Assistant General Secretary, P.O. Box 6894, Johannesburg. 



CORRESPONDENCE. — All communications other than those relating to 

 the Journal should be addressed to the Assistant Secretary, P.O. Box 6S94, 



Johannesburg. (Telegraphic address: "Science, Johannesburg.") 



Communications for the Editor should be addressed to P.O. Box 1176, 

 Johannesburg. 



MANUSCRIPTS for pu])lication sl)ould ])e typewritten. 



ILLUSTRATIONS (other than photographs) accompanying papers intended 

 for publication in the Journal must be supplied by the authors, carefully drawn 

 about twice the size of the finished block, on smooth white Bristol board, in 

 Indian Ink, so as to admit of the blocks being prepared directly from the 

 drawings. Any lettering on these drawings should be of such a size that it 

 will be clearly legible when reduced. 



REPRINTS. — Authors desiring to have reprints of their papers, read at 

 the Annual Meeting of the Association, are requested t-o notify the Editor as 

 to the number required when returning their proofs. 



LOOSE COVER CASES. — Cases uniform in all respects with the covers 

 of previous volumes may be obtained for binding vols, vi (1909) to xv (1918), 

 on application to the Assistant General Secretary, at a cost of Is. per case, 

 and 6d. for postage. 



BINDING VOLUME XVI.— The publication of vol. xvi of the Journal, 

 comprising the papers read at the Kiiigwilliamstown (1919) meeting, is now 

 completed. Members desiring to have their separate numbers of this volume 

 bound should forward them to the Assistant General Secretary, and inform 

 him of their wislies, by 1st February, 1921, when the orders will be given to 

 the binders. 



SUBSCR5PT5 0NS. — Subscriptions of £1 for the year ending 30th June, 

 1921, are now due. Members are requested to be so kind as to remit the 

 amount as soon as possible to the Assistant General Secretary, P.O. Box 6894, 

 Johannesburg. Unless members pay the amount due at an early date, great 

 inconvenience and unnecessary expense may be caused, as it is very difficult 

 to determine v.hat number of copies of the Journal will be required. The 

 Council therefore appeals to every member for support and co-operation, and 

 asks that outstanding subscriptions be. paid without delay. The Journal will 

 be ssp.t only to thass uhoso arrear subscriptions are paid. 



Cheques, etc., should be crossed and Tuade payable to the Association, 

 not to the Secretaries or Treasurer individually. Sixpence should be added to 

 country cheques for exchange. 



CHANCE OF HEADQUARTERS.— Attention is called to the change of 

 Headquarters decided on at the Kingwilliam.stown (1919) ses.sion. In future 

 the office address of the Association will be " P.O. Box 6894, Johannesburg " ; 

 the telegraphic address will be " Science, Johannesburg," and the telephone 

 Bumber " 1404, Johannesburg." 



Johannesburg, loth November, 1920 



