Chilling Wheat Blooms Makes Crossing Easier.--Severe chilling of wheat plants--either by natural frost or by artificial refrigeration --is a promising new tool for plant breeders who are working to develop new varieties of wheat with special qualities such as drought resistance, winter hardiness or disease immunity. COlT A. SUNE-sON of the Bureau of Plant Industry, U. S. Dept. of Agriculture, has announced results of experiments in which by chilling them he emasculates the heads of the wheat plants, killing the pollen and thus preventing the normal self-fertilization of the wheat florets, and at the same time opening up the head so that it was easy to apply pollen collected from another variety of wheat. Working at Lincoln, Nebraska, Mr. Suneson brought the wheat plants to the stage where heads were forming but had not emerged from the protective sheath. At this stage temperatures of 27 to 32 deg. F. killed the pollen but did not kill the pistillate parts of the flowers, and as the heads emerged from the sheath the protecting tissues were left open. Thus it was easy to dust the emasculated head with foreign pollen and so make a quick and easy crossing. By making crosses in this relatively quick and easy way, it may be possible, says the Bureau, to make more rapid progress in developing new wheat varieties with specific desirable qualities. By making many crosses and selecting desirable plants from the offspring, the breeder would improve his chances of getting just the desired combination promptly. At best, plant breeders explain, the search for new hybrids is something of a gamble in that large numbers may be required to get the desired combination through the operation of chance alone. Any device that will improve the odds and allow the breeder wider choice from the same skill and effort is a tool that is likely to prove valuable. R. H. O.