Stephen T. Franklin, Speaking from the Depths: Alfred North Whitehead's Hermeneutical Metaphysics of Propositions, Experience, Symbolism, Language, and Religion. 1990, Wm. B. Eerdmans Publishing Co: Grand Rapids, Michigan.
The wording here is somewhat complicated, to say the least. The idea of transmutation itself, however, is quite simple. For an explanation of transmutation, consider diagram 1. The rectangular boxes are the dative past actual entities. L, M, and N are simple physical prehensions of those entities. The diagram has "pipes" from L, M, and N to their respective past actual entities. The pipes represent either pure or hybrid physical prehensions. L, M, and N, along with all other simple physical prehensions (which are not shown) constitute the first, conformal stage of concrescence.
suggested by Dan Royer