Abstract
Polyacrylamide disc electrophoresis of plasma proteins and starch-gel electrophoresis of hemoglobins and muscle myogens of adult and ammocoete forms of three species of Great Lakes lamprey were carried out. Blood proteins were shown to undergo marked changes upon transformation of the ammocoete into the adult form. Muscle myogen did not undergo any change during transformation. The muscle myogen electropherograms of Ichthyomyzon unicuspis and Lampetra lamottei were found to be the same.