Ferment, a sign of progress in any scientific field, has previously been lacking in the area of cryptorchidism, where the only activity has been in improving operative methods. Now, however, profound changes in the care of boys with cryptorchidism are being brought about; ideas are arising from a fresh look at comparative anatomy, and histological and experimental observa tions are being supplemented by clinical tests made possible by new hormonal agents. The treatment of cryptorchidism begins with its recognition by the pediatri cian, who until now has shown little interest because of...