“…The average chain weight is about 25 000. This value and the nature of the chief end groups are, with the exception of alanine, at variance with the results of Haley (1955) and Luck et al (1956), which were obtained with histones prepared by extraction with sodium chloride and hydrochloric acid of thymuscell nuclei. In whole-thymus histones these authors found that valine accounted for 53 % of the Nterminal residues, leucine for 21 %, alanine for 18 % and glycine for 8 %.…”