This paper gives an historical review of the results of researches upon the different radiations which are present on the surface of the earth; especially, cosmic radiation is discussed in some detail. Systematic measurements in houses, by the author, have shown that the intensity of the radiations varies a great deal even within the same house due to the varying content of Ra and Th in the building materials. As there is no question that very small intensities of radiation have a biological effect, one must expect an effect of these radiations upon the processes of life. For this purpose the germinating of Raphanus sativus and the development of Drosophila melanogaster were studied in a vessel with an iron wall of 15 cm. thickness. The temp. was kept constant. The comparison with the controls showed that the % of germination was smaller within the vessel but the development per individuum quicker. Similar results were obtained with Drosophila.