Testicular function is known to be intimately connected with the growth of the penis and its erectile power, the growth and maintenance of the secondary sex glands, the maturation of the skeleton and the growth, and in some species the maintenance, of the secondary sexual characteristics. Chemical substances which have pharmacologic properties similar to those of testicular extracts have been isolated from human urine and animal adrenals, and they have been demonstrated in other tissues. Such substances are called androgens. Many androgens, some of which are known to occur in nature, have been produced artificially from sterols. Koch1 has recently published a comprehensive review of the literature dealing with these facts.
Moore's2 experiments showed that testis extracts produced evidence of damage to spermatogenesis, and he stated that testis hormones could not be used clinically without probable harm to the production of sperm. Walsh, Cuyler and McCullagh3 in