Summary— Ascent of the testis from the normal to an undescended position has been observed in 10 patients. In 9 of them there was a complete hernial sac and it is suggested that the acquired malposition of the testis is due to partial absorption of the processus vaginalis into the parietal peritoneum. Alteration in the length of the inguinal canal with growth may be an additional contributory factor. The mean interval between the original and subsequent observations was 5.2 years, leading to a late orchiopexy at a mean age of 9.4 years.