‘X body' was first observed in spermatozoa of insects by

Henking (1891) could trace a specific nuclear structure all through spermatogenesis in a few insects, and it was also observed by him that 50 per cent of the sperm received this structure after spermatogenesis, whereas the other 50 per cent sperm did not receive it. Henking gave a name to this structure as the ‘X body’ but he could not explain its significance. Further investigations by other scientists led to the conclusion that the ‘X body’ discovered by Henking was in fact a chromosome and that is why it was given the name X-chromosome.