Encyclopedia of Electronic Components - Vol1, pg:98 by Charles Platt
Electrons from the power source will migrate on to the plate attached to the negative side of the source, and will tend to repel electrons from the other plate. This may be thought of as creating electron holes in the other plate or as attracting positive charges,
Isn't this dead wrong! Electrons don't migrate from the source (battery, power supply). Electrons aren't little rolling balls that leave the battery on a journey to the dielectric where they polarize atoms!
Instead, the battery/PSU provides a Electric field (that travels at c=speed of light approximately) that polarizes the dielectric across a region of space within it; electrons are displaced from their favorite haunts around their home atoms and you won't find them there anymore (or you might - the probability distribution is altered).
This does not create a hole, or ion! A hole is the promotion of a valence band electron into the conduction band where it's free to move about in the material lattice.
What is important is that a capacitor stores an electric field by aligning it's (atoms, molecules - charge carriers) in one way.
Maybe electrons in the wire will move into the battery and cause a chemical reaction that is used to maintain the Electric field.
So that para is wrong -right?
One thing i don't understand though is why, when the cap is disconnected, it still retains the orientation (in the absence of the external E-field).