LrttrntOthEditor May be a r b m i via ernait (at xiere-letters 6saaarog), fax (202-789466B), or regular mail (kr' .;eKe, I F Z O O New York Awenue, NW, W m gton DC 20005, USA). LetWs are not routinely. acknowledged. Full addresses, signatures, and daytime phone numbers should be included. Letters should be brief (300 words or lea) and may be e d i i for clarity or -.They may appear in prht Worw the,dnbalat Letter mitersarenetcor&lbbedbdmpubbth. ---Far change abf address, midrig issues, new orckrs and wmoiwds, a d payment questions, ~c o n M~a t~, m 8 0 0 -7 3 1 -4939 or Wash&$m C G 292*3&6417, FAX 202-842-lWS. MaZlirlg &&~ss% MAS. P.O. W 1811, Bdttf$cTDhBt30rAMS Maonber Service&, 1 LO@ FEkw Yok Avenue, NW. Washington, BC -5 * Other AAAS Prom 202-326--~~ For Wit C a d M N A 1-8QO-847-7378; Car Betchart Expeditions 1-800-252-4910; Life Insurance: Seabury & Smith 1-800-424-9883; Other Benefits: AAAS Membet swvice5 1-202-326-641 7. R.prinb ~~I l i n g / S t 8 t u s 800-407-9190; Correct&ms 202-326-6501 PennWons 202-326-7074, MX 202682-OB16 I n t M . t M h s s e s s d e n c e c e~a a a s . o r g [for g d editorla1 queriesf; sciencee~s8aaas.org (for news queriesl; sa'ewe-~e~aaas.org (for Letters to the editor); science-reviews@aaas.org (for returning manuscript mviews1; science-1 bookms@aa&.org (h iKlok review queries); scien&&dence-iRtcoRtco~k (for Ehe Europe Office); membenhip@aaasorg member wrvices); science-dasslfieds@aaw.org (for submitting classified advertisements); science~~n @~o g (for pdud advert-) ~I r N a m c O n b c t a NerM hnerka 1200 New York Avenue, NW. W i DC MQ05 Mitorid: 202-326-6K,l. FAX 202-289-7562 Ncw* 202-326-6500, FAX 202-371-9U7 Bureau% m, 510652-0302, FAX 510-652-1867, San Diego, C k 760-942-3232, FAX 760-942-4979, 111: 312-360-1227, FAX 312-3604537. Pseffk Northwest: 541-3426290 ~~~H a u S e , 8 2 -8 B # I l s R o a d ,~U K c B 2 1LQ:(44) 1=326500, FAX (44) 1223--1 Paris Conerpandent: (33) 1-49--1, FAX (33) 142949-00 Ad. Nrws Bumw DcMis N a m i k (81) 33335-9925, FAX (81) 3-333--m Japan O M Axa CMporation, Eiko lshioka, Fusab Tamraa, 1 -8 -1 3 , 3 , h k u , Osaka-shi, Osaka. 541 japan; (81) 6202-6272, FA% (81) 62026271; aw&b&f.tor.jp China Offia Hao Xi% (86) 1WS5-947& sdem&wb-