Last spring, while collecting beetles under the bark of decayed logs, I met with numbers of the larvæ of Arctia isabella (hairs brown in the middle, black at each end of larva,) about to spin up. Not knowing their hybernating habits, they had always baffled me, and under the impression that they would require another season to mature, had been turned loose. I collected some twenty, put them into a box with cotton and paper scrap, and they at once spun up, all but four. These wandered up and down for a week, having some want, and wasting away.