CORBET: May I welcome you to the fourth of our plenary seminars which have been a feature of each of the last three S.I.O. International Symposia? These Symposia have been informative and enjoyable and, as I said the other day, they offer an opportunity to exchange Information and experiences in an informal way. In the two previous Symposia the plenary sessions have been recorded very effectively and then transcribed and presented in an edited transcript in the S.I.O. Rapid Communications series under the title “Current Topics in Dragonfly Biology” (1,2). I hope that we shall be able to do that with the discussion today.