Sweden (Continued) for each sample and one caesium ratio chemical determination in a pooled sample. A second part of the report describes a cuU.uecting procedure using ion exchange resins. G/R.145 UPTAKE OF STRONTIUM AND CAESIUM BY PLANTS GROWN IN SOILS OF DIFFERENT TEXTURE AND DIFFERENT CALCIUM AND POTASSIUM CONTENT G/R.146 THE RADIOACTIVE FALLOUT IN SWEDEN UP TO 1/7/57 Additional data to the report G/R.15 for the period up to June 1957 are given. The total activity, accumulated Sr® and Cs'*? amount and Sr® contentin soil are measured. G/R.147 G/R.148 GAMMA RADIATION IN SOME SWEDISH FOODSTUFFS Significant increase of radiation in milk, beef, cattle-bone, and vegetables was found during the period 1952-1956. No increase of gamma radiation in children in the corresponding period could be observed. PROGRESS REPORT ON THE METABOLISM OF FISSION PRODUCTS IN RUMINANTS The excretion of radioactive fission products (Srand I'*!) in milk after oral administration is measured. G/R.149 A METHOD FOR MONTHLY COLLECTION OF RADIOACTIVE FALLOUT Describes a collecting procedure using anion and cation exchange resins. G/R.150 THE COMPUTATION OF INFINITE PLANE 30-YEAR DOSES FROM RADIOACTIVE FALLOUT Proposes new method for evaluation of the external 30-year dose due to the deposition of gamma emitting isotopes, based upon a single beta measurement for each sample and one Cs!"" ratio chemical determination in a pooled sample. G/R.151 THE CONTROL OF IRRADIATION OF POPULATIONS FROM NATURAL AND ARTIFICIAL SOURCES Describes an automatic system for continuous indication and recording of very low radiation level; suggests the use of such instrument for public control purposes. G/R.173 TRANSFER OF STRONTIUM-90 FROM MOTHER TO FOETUS AT VARIOUS STAGES OF GESTATIONIN MICE Shows that no significant fixation of sr”? by the foetus can be detected before the 15th day of gestation. The increase of radioactivity corresponds with the intensity of ossification processes. G/R.174 THE RECOVERY PHENOMENON AFTER IRRADIATION IN DROSOPHILA MELANOGASTER 1. Recovery or differential sensitivity to X-rays. Experimental results: lower rate of chromosome aberrations induced by X-ray if irradiated in anoxia in comparison with irradiation in air. Supports the hypothesis of recovery. G/R.174 (Add.1) THE RECOVERY PHENOMENON AFTER IRRADIATION IN DROSOPHILA MELANOGASTER Indicates that both the spontaneous recovery and the differential sensitivity in sperm’s genesis in Drosophilaare responsible for the changes in the rate of chromosomebreaks under conditions of irradiation. G/R.174 (Add.2) THE RECOVERY PHENOMENON AFTER IRRADIATION IN DROSOPHILA MELANOGASTER 188