IN the report for 1937 of the Strangeways Research Laboratory, Cambridge, the trustees are able to announce that an anonymous donor has guaranteed an additional £500 a year to the income of the trust for five years. This subscription has enabled the trustees to accept the offer of the Rockefeller Foundation of the capital cost of an extension. The new buildings will provide additional accommodation for laboratory work, and will enable satisfactory arrangements to be made for the library and the workshops. During the year, the record number of twenty-five persons has worked in the Laboratory, and it is a testimony to its reputation that of these, eleven should be visitors from other laboratories in Great Britain and abroad. The British Empire Cancer Campaign has equipped the Laboratory with a 200 kv. X-ray apparatus, and has purchased a 300 mgm. radium plaque, which had been on loan. This has enabled the Work on the irradiation of tissues to be continued, and it is now being extended from the preliminary observations in vitro, to the more difficult problems encountered in vivo. Of the sixteen papers published from the Laboratory during the year, nine are concerned with embryological problems, three with the effects of radiation on living material, and the remainder with the metabolism of tumour tissue and the physiology of the embryonic heart.