The steady withdrawal of the ego causes the particles of the astral body gradually to cease to function. The time taken for this process varies within very wide limits and it entails arrangement of layers by degree of density with the densest being outside.
The astral body thus disintegrates as the consciousness is gradually withdrawn from it. During the interval of falling asleep at the close of the astral period and prior to the awakening on the lower mental plane, the last of the separation of matter of the two planes takes place.
An imprint of the experiences on the astral plane is retained by the now abandoned astral corpse, which is in a state of disintegration. As at the time of death on the physical plane an imprint of all the experiences undergone during one’s life on earth was gathered and stored by the individual life force, similarly an imprint of the experiences on the astral plane will remain stored within the individual life force to be used in the future when the new astral body will be constructed having exactly similar potentialities and capacities that the last one had.
In each of the three worlds, physical, astral and mental, these imprints store the total vibratory capacity that has been developed by the soul or individual life force throughout the ages of its evolution in those levels of matter.
This is another fine example of the provision of the necessary tools by nature for the evolution of man towards perfection. Slowly the ego draws into itself the memories of the earth and astral life just ended and it prepares to pass out of Kamaloka into the blissful state of devachan or the lower mental plane/heaven world.
It may be said briefly that the period spent in devachan, is the time for the assimilation of life experiences, the regaining of equilibrium, where a new descent into another incarnation is undertaken.
When one passes out of the astral plane into devachan, any thought-forms of an evil nature cannot be carried there as astral matter cannot exist on the devachanic level. Devachanic matter cannot answer to the coarse vibrations of evil passions and desires.
Consequently all that one may carry, when one finally shakes off the last remaining remnants of one’s astral body, will be the latent tendencies which when they can find an outlet in another incarnation, will manifest as evil desires and passions once again in the astral world.
These lie dormant throughout one’s life on the lower mental or devachanic plane.
The final struggle with the desire-elemental takes place at the conclusion of the astral life, for the individual life force is then endeavouring to draw back into itself all that it put down into incarnation at the beginning of the life which has just ended.
When the individual life force attempts to do this it is met with determined opposition from the desire-elemental, which the individual life force has created and fed. In the case of ordinary people, some of their mental matter has become so entangled with their astral matter that it is impossible for it to be entirely freed.
The result of the struggle is that some portion of the mental matter, and even of causal (higher mental) matter is retained in the astral body after the ego has completely broken away from it.
On the other-hand, if during the life just completed one had conquered one’s lower desires and succeeded in absolutely freeing the lower mind from desire, there is practically no struggle and the ego or individual life force is able to withdraw not only all that it had invested in that particular incarnation, but all the interest, i.e., the experiences, faculties etc., that had been acquired. There are also extreme cases where the ego or individual life force loses both the capital invested and the interest, these are known as lost souls or elementaries.