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. He gave a name to this structure as the X body but he could not explain its significance. Mc Clung contributed to chromosmal theory of sex determination worked on grasshoppers. Bridges proposed gene balance theory by working on Drosophila. Morgan work contributed theory of chromosomal theory of inheritance