A measure of the total mass accretion of meteoritic material by the Earth is obtained from analyses of deep sea sediments and dust collected in remote regions (Pettersson, 1960). Most meteoritic material, by the time it reaches the Earth's surface, has been reduced to dust or to spherules of ablated material in its passage through the atmosphere. For all meteorites, the average nickel content is about 2.5 per cent. This is much higher than the nickel content of terrestrial dusts and sediments and provides a basis for the determination of the meteoritic mass influx. Present data indicate an accretion of about ** f tons per year over the entire globe, or about ** f.