1 Alonzo Church, Ann. Math., 2nd ser., 33, 346-366 (1932), and 34, 839-864 (1933). S. C. Kleene, Ann. Math., 2nd ser., 35, 529-544 (1934). We shall refer to the latter paper as Kleene 1934. 2 Alonzo Church and J. B. Rosser, "Some Properties of Conversion." 3 Explicit formal definitions are given by S. C. Kleene, Amer. Jour. Math., 57, 153173 (1935). This paper, and a second part of it, forthcom...

THE importance of the physiologically active substance acetylcholine makes it highly desirable that the properties of the enzyme which specifically hydrolyses choline esters be established. Summaries of the past work on this enzyme have recently appeared [Ammon, 1935; Gaddum, 1935; Oppenheimer, 1935]. It is remarkable that although choline esterase has been studied in relation to its partial pu...