But only by a form of vital dynamic correspondence, a sort of magnetic interchange.

The idea does not intervene at all.
Gradually, however, the dark shadow of our object begins to loom in the formless mind of the infant.

The idea of the mother is, as it were, gradually photographed on the cerebral plasm.

It begins with the faintest shadow--but the figure is gradually developed through years of experience.

It is never quite completed.
How does the figure of the mother gradually develop as a _conception_ in the child mind?
It develops as the result of the positive and negative reaction from the primary centers of consciousness.