The activity of the cytochrome system in muscle and its relation to myoglobin

sistently present, and if so whether they indicate important peculiarities in the sexual biochemistry of the animals concerned. SUMMARY 1. A 7-dehydrosterol, presumably 7-dehydro- cholesterol, was detected spectrophotometrically in high concentrations in the caput epididymis, corpus epididymis and preputial glands ofmale rats, and in the bulbivestibuli offemale rats. It could not be detected in other parts of the male or female genital systems.