Note 181 — LETTER XIX.
Reading edition
This conjecture receives strong confirmation from the following observations of Sir E. Home, which I met with since it came into my mind. From the nipples present in man, which sometimes even afford milk, and from the general analogy between the male and female organs of generation, he supposes the germ is originally fitted to become either sex; and that which it shall be is determined at the time of impregnation by some unknown cause. Philos. Trans. 1799. 157.