By means of molecular exclusive chromatography, a marked difference in the distribution of desmosine and isodesmosine in the products of proteolysis has been found between the partial enzymatic hydrolysates of elastin from the bovine nuchal ligament prepared by two different methods. In the preparation which was treated with hot NaOH the prevailing portion was localized in a macromolecular fraction corresponding to the void volume. An increased precipitation of this fraction with trichloracetic acid has been noticed. The autoclaved material forms substantial amounts of the coacervate during the digestion.