Free amino-acids in the yolk during the development of the chick.

THE progressive appearance of free amino-acids in the yolk during the development of the chick have been examined by paper chromatography, and we have observed that the density of the spots, from comparable aliquots, of yolks from fertilized hen's eggs increased from the fourth to the tenth day and decreased after this to the twelfth. To test these observations by an additional approach, similar samples were chromatographed on ‘Dowex’1 and the results are reported here.