890 ADVENTURES IN RADIOISOTOPE RESEARCH 



the endosperm. In the case of the pea, there is no such marked distinction 

 between germ and endosperm, the cotyledons occupying most of the 

 space inside the seed, so that the labelled phosphorus atoms are taken 

 up by the different parts of the seed. The concentration of the labelled 

 phosphorus in the leaves and rootlets was here considerably higher than 

 in the rest of the seed (cotyledons), as is seen from Table 3. 



Reference 



l.G. Hevesy, K. Linderstr0m-Lang and C. Olsen, Nature 137, 66 (1936). 



