1. Some of the recessive abnormalities induced by X-rays in E. coracana Gaertn. and Pennisetum typhoides S. & H. are described. 2. In E. coracana are described a chlorophyll deficiency in which the first two or three leaves are green and white banded, but the mature plant is fully green and two mutations effecting the panicle. In P. typhoides have been noted gappiness, tip-sterility, forking and goose-necking in the panicle, male-sterility, and weak-midribbed leaves all behaving as recessives. 3. While some of the plant characters in both these millets mutated easily, others showed no tendency to mutate. Thus in E. coracana the panicle shapes and chlorophyll factors mutated while the grain colour, length of glume and growth factors did not give any mutations, while in P. typhoides the greatest number of mutations were observed in the chlorophyll and panicle characters. 4. P.typhoides threw out more mutations than E. coracana and this is adduced to the diploidy of the former and the tetraploidy of the latter
