The world is endlessly fascinating, countlessly full of interesting people. Once at a party long ago I met a visitor to Guyana who turned out to be an expert on grass-hoppers. He was a great enthusiast and I spent an hour talking to him about grasshoppers around the world and could easily have spent another day or a week on the subject. I did not know, until he told me, how full the world is of grasshoppers – green and gold and brown and black and red even, some inches large and some dot-like small, with a thousand sounds and songs and habits of their own. If you should cut down one of your great forest trees, he told me, in the branches of the crown, if you look carefully enough, you will find twenty or more separate species of grasshopper there. This visitor was going up the Essequibo for a few days and was looking forward to discovering at least a handful of completely new kinds of grasshopper to add to his collection. There was going to be a full moon and apparently there are some grasshoppers that are especially attracted by a combination of the moon and the sweet sap in the leaves of a certain kind of tree he hoped to find.