Samdhinirmocana Sutra [trans. Powers, note 4, chapter 5]
On transmigration and predispositions:
W = Wonch'uk - Arya-gambhira-samdhinirmocana-sutra-tika
B = Byang-chub-rdzu-phrul - Arya-samdhinirmocana-sutra-vyakyana
VJ = Hsuan-tsang - Vijnaptimatratasiddhi
(W) "On the occasion of taking birth in those transmigrations, initially when making the transition between lives, the mind that is a consciousness [containing] all seeds ripens". The mind forms because (B) "at that time, in terms of birthplace, the aspect of the form that is the combination of the semen and blood of father and mother and the basis-consciousness move into a womb and become an establishment and an abiding". The mind "develops... due to continuous operation subsequent to that". Increase takes place "at the time of the arising of the operating consciousness". The mind expands "due to the infusion of predispositions by those operating consciousnesses".
At the beginning of a new life, a being has the karmic latencies of past lives (referred to as seeds), which begin to manifest themselves in the new continuum. They then grow and develop, and as the new life progresses, they in turn lead to production of new predispositions, and so the process continues and maintains itself.
In a previous discussion of the basis-consciousness (W) comments: "Due to the basis-consciousness, through the force of maintaining the three types of predispositions, the continuity of the gap between lives is not cut off". According to (VJ), the three types of dispositions are: (1) predispositions of verbalisation (Skt. abhilapya-vasana), (2) predispositions of apprehending a self (Skt. atmagraha-vasana); and (3) predispositions of the limbs of cyclic existence (Skt. samsaranga-vasana).
The first type (1) includes seeds that predispose a person to make differentiations regarding individual compounded phenomena. These are of two types: (1-a) manifest expressions that define meanings, which are expression of vocal differentiation with respect to meanings; and (1-b) manifest expressions that define objects, which are phenomena of minds and mental factors that understand objects.
The second type (2) includes seeds that predispose one to incorrectly conceive 'I' and 'mine'. These are also of two types: (2-a) innate conceptions of self, which are conceptions of 'I' and 'mine' which are to be discarded by a path of meditation; and (2-b) the imputational conception of 'I' and 'mine' that is an object to be abandoned by the path of seeing.
Due to these two conceptions, sentient beings make distinctions of 'self' and 'other'.
The third type (3) of predisposition includes seeds that induce fruition of the three realms of existence. These are also of two types: (3-a) virtues associated with contamination, which are any actions that induce desirable effects; and (3-b) non-virtues, which are any actions that induce undesirable effects.