Karrer and Enslin^[2] reported that the structure of alstyrine (S₁₉H₂₂N₂), a selenium-dehydrogenation-degradation product obtained by Sharphl from the alkaloid alstonine, is identical with that of corynanthyrine, a-(2-(4, 5 diethylpyridyl)]-β-ethylindole (Ⅱ), despite the fact that the melting points of these two substances have a 50 difference. In his investigation, the author of the present paper has synthesized two homologues of (Ⅱ), a-(2-pyridyl)-β-methylindole (Ⅲ) and a-(2-pyridyl)-β-ethylindole (Ⅳ), finding that the former has almost