Bhavanga-citta: 'subconsciousness' bhavanga-citta is a kamma-resultant state of consciousness vipāka, and that, in birth as a human or in higher forms of existence, it is always the result of good, or advantageous kamma kusala-kamma-vipāka, though in varying degrees of strength see: patisandhi, end of the article. The same holds true for rebirth consciousness patisandhi and death consciousness cuti, which are only particular manifestations of subconsciousness. In Vis.M XIV it is said:
As soon as rebirth-consciousness in the embryo at the time of conception has ceased, there arises a similar subconsciousness with exactly the same object, following immediately upon rebirth-consciousness and being the result of this or that kamma intentional action done in a former birth and remembered there at the moment before death. And again a further similar state of subconsciousness arises. Now, as long as no other consciousness arises to interrupt the continuity of the life-stream, so long the life-stream, like the flow of a river, rises in the same way again and again, even during dreamless sleep and at other times. In this way one has to understand the continuous arising of those states of consciousness in the life-stream. Cf. viññāna-kicca .
Maha Thera Nyanatiloka. Manual of Buddhist Terms and Doctrines, Buddhist Publication Society, first edition 1952.