In the first report (vol. vi. p. 450) we described several series of experiments which had as their object the determination of the relative importance of the Indian rat flea, Palex cheopis, and of actual close contact in the absence of fleas in the dissemination of plague from animal to animal. These observations were carried out in a series of small godowns or cabins, which were built especially for the purpose. The experiments which we have now to put on record are a continuation of those already published. They were carried out during the non-plague season of 1906 and the plague season of 1907.