" This hypothesis is inevitably controversial, but it is testable by experiment, and there is already considerable circumstantial evidence in its favor. For example, when a newly synthesized organic chemical is crystallized for the first time (say a new drug), there will be no morphic resonance from previous crystals of this type. A new morphic field has to come into existence; of the many energetically possible ways the substance could crystallize, one actually happens. The next time the substance is crystallized anywhere in the world, morphic resonance from the first crystals will make this same pattern of crystallization more probable, and so on. A cumulative memory will build up as the pattern becomes more and more habitual. As a consequence, the crystals should tend to form more readily all over the world.

Such a tendency is in fact well known; new compounds are generally difficult to crystallize, sometimes taking weeks or even months to form from supersaturated solutions. As time goes on, they tend to appear more readily all over the world. "

― Rupert Sheldrake , The Rebirth of Nature: The Greening of Science and God