...namely the Yesods... In the human form it is obvious that there is a genuine and complete difference between the organs of reproduction of the male and female. This shows that it is here that the root of the difference lies, because aside from this, both male and female consist of 613 parts and other shared aspects. Where they differ is in the way they draw down their influence. The truth is that there is a difference between male and female in everything relating to the Yesod. The proof case is that of the castrate (who has no beard, etc. – a change in form that depends on the Yesod).