Hopefully, it will never again be possible to repeat the studies reviewed in this paper, as in more recent times we have used different means of expressing man’s inhumanity to man. It is to the credit of the pioneering physician scientists involved that useful medical information was obtained about the long term effects of castration, under circumstances that must have been difficult, from the study of these now extinct groups of castrated men, and it is impressive that all their findings (osteoporosis, failure of closure of the epiphyses, reactive pituitary hyperplasia, shrinkage of the prostate, and development of gynecomastia) have been confirmed subsequently by studies of individuals or small groups of individuals with various forms of hypogonadism.