The woman now feels for the first time as a true wife might feel.

And her feeling is towards her son.
Or, instead of mother and son, read father and daughter.
And then what?
The son gets on swimmingly for a time, till he is faced with the actual fact of sex necessity.

He gleefully inherits his adolescence and the world at large, without an obstacle in his way, mother-supported, mother-loved.

Everything comes to him in glamour, he feels he sees wondrous much, understands a whole heaven, mother-stimulated.

Think of the power which a mature woman thus infuses into her boy.