A study was made of the effect of vit. C on development and function of gonads in white rats 2-4 mos. old. 4 groups of 12 animals each were used. From each group 4 animals were injected with 25 R.U. of gonadotrophic hormone and 50 mg. of ascorbic acid simultaneously, 4 others with 25 R.U. of the hormone alone and 4 with 25 mg. of the yit. only. The results were compared with 4 groups of uninjected normal rats. Simultaneous inj. of gonadotrophic hormone and ascorbic acid for 20-30 days produced a greater increase in development of testes and peni and of [female] genitalia than the hormone alone. The increase was almost doubled by combined treatment as compared with the hormone alone, whereas ascorbic acid by itself produced no change in gonad size in normal rats.