An experimental study on the life‐history of hypotrichous infusoria

From November 20 to 24, in the third period, A-I and A-z were changed from the hay-infusion to a medium of flour and water, prepared by boiling a pinch of flour in about 25 cc. of tap-water for fifteen minutes.This change of medium was made because I became alarmed at the rapid fall in the division-rate-not having become acquainted, as yet, with the general life-cycle of hypotrichous forms.That the use of the flour had no apparent effect was shown by a comparison with the division-rate of A-3 and A-4 which were continued on the hay-inf ision dietThis was used about an hour after cooling.