A substance toxic to the parasitic sea lamprey, Petromyzon marinus, which preys upon commercial fish species of the Great Lakes: Scherer et al., DE 1068505 C.A. 55, 9774d (1961) corresp to US 3157571 (1959, 1964, both to Hoechst). Toxicological studies in fish, and bibliography: Kawatski, McDonald, Comp. Gen. Pharmacol. 5, 67 (1974). Physical properties: Smith, J. Chem. Eng. Data 6, 607 (1961). Review: Schnick, Investigations in Fish Control, no. 44 (Sport Fisheries and Wildlife Bureau) 31 pp.