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

 page. Every 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 Goneral Secretary, P.O. Box 6391, Johannesburg. 



CORRESPONDENCE. — All communications other than those relating to 

 the Journal should be addressed to the Assistant Secretary, P.O. Box 6394, 

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



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

 Johannesburg. 



PAPERS for publication should be typewritten. 



ILLUSTRATIONS (other than photographs) accompanying papers in- 

 tended for publication in the Journal must be supplied by the authors, care- 

 fully 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 to notify the Editor 

 as soon' as possible as to the number required, or, at latest, when returning 

 their' proofs. 



LOOSE COVER CASES.- — Cases uniform with the covers of previous 

 volumes may be obtained for binding recent Reports on application to the Assistant 

 General Secretary, at a cost of 4s. per case post free. 



BINDING VOLUME XVII The publication of Vol. xvii of the Journal, 



comprising the papers read at the Bulawayo (1920) meeting, is com- 

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

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

 him of their wishes,, when the orders will be given to the binders. The cost 

 of the cover and binding will be 12s. 6d. post free. 



VOLUME XVIII., comprising the papers read at the Durban (1921) meet- 

 ing, is completed in this double number. The volume can be bound for 9s. 

 post free. Arrangements should be made with the Assistant General 

 Secretary, as above. 



SUBSCRIPTIONS.— Subscriptions of £1 108. for the year ending 

 30th June, 1922, 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, at 

 it is very difficult to determine what number of copies of the Journal will b#> 

 /equired. The Council therefore appeals to every memoer for support and 

 <o-operation, and asks that cutstanding subscriptions oe paid without delay. 

 The Journal will be sent only to those whose arrear suoscriptions are paid. 



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

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

 to country cheques for exchange. 



HEADQUARTERS,— The office address of the Association now is "P.O. 

 Box 6994, Johannesburg" • the telegraphic address is "Science, Johannes- 

 burg," and the telephone number "1404, Johannesburg." 



Johannesburg, 80th June, 1922. 



