Cryptorchidism (over 90% in some studies). Even after orchiopexy, these may also affect sperm maturation and motility at an older age. The most common diagnostic dilemma in otherwise normal boys is distinguishing a retractile testis from a testis that will not descend spontaneously into the scrotum. Retractile testes are more common than truly undescended testes and do not need to be operated on. In normal males, as the cremaster muscle relaxes or contracts, the testis moves lower or higher ("retracts") in the scrotum. This cremasteric reflex is much more active in infant boys than older men. A retractile testis high in
From the Earth to the Moon (especially cannons), comes together when Impey Barbicane, its president, calls them to support his latest idea. He's done some calculations, and believes that they could construct a cannon capable of shooting a projectile to the moon. After receiving the support of his companions, another meeting is held to decide the place from which the projectile will be fired, the dimensions and materials of both the cannon and the projectile, and which kind of powder they are to use. An old enemy of Barbicane, a Captain Nicholl of Philadelphia, designer of plate armor, declares that the entire enterprise is absurd and