Martin J. Canny is honorary research professor at Carleton University. He earned a Ph.D. at Cambridge University. He has been a research chemist at the Imperial Chemical Industries of Australia and New Zealand, a lecturer in botany at Cambridge University and a foundation professor of botany at Monash University, Australia. Address: Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6. Internet: mcanny@ccs.carleton.ca.