Mythical 'Tails of Lockwood'

The cause of testicular ectopia has long been a mystery, and over the years, many hypotheses have been suggested to explain the condition. The most famous of these hypotheses is that of the 'Tails of Lockwood'. This developed from a paper written in 1888 by Charles Barrett Lockwood. Although little evidence has ever been found to corroborate this hypothesis, it remains in many textbooks and journal articles to the present day. In the 21st century, this theory should no longer be given as the cause for ectopic testes. Current biological evidence supports a complex process of growth, by elongation and migration of the gubernaculum, rather than a simple mechanical process of testicular descent, as proposed in the 18th century.