During the summer of 1882 a few of the ash trees on the college lawn became infested with a Saw-fly worm which for a few days threatened to be quite serious. I made a few trials of London purple on the trees most seriously infested, but before I had gained results from many trees or had completed a study of the larvæ, they suddenly disappeared. So far as my experiments went they showed the London Purple to be a successful remedy and as applicable to these worms as to any of the Saw-Fly group. No adults were observed, and none of the larvæ I had under my observation matured; so the matter necessarily came to a rest.