The amount of spermin in human testis, muscle, brain, milk, liver, and pancreas ranged in order from .003 % by weight in the testis to .054% in the pancreas. In human sperm preserved in alcohol the spermin content was .38%. In cow muscle, testis, prostate, and pancreas the spermin content of the pancreas was greatest, .087%, and least in muscle, .01 %. Traces of spermin occurred in cow''s blood and in considerable amount in brewer''s yeast where the determination was not quantitative.