The Collaborative International Dictionary of English v.0.48:

Ovism \O"vism\, n. [Ovum + -ism.] (Zool.)
   The old theory that the egg contains the whole embryo of the
   future organism and the germs of all subsequent offsprings
   and is merely awakened to activity by the spermatozoon; --
   opposed to spermism or animalculism.
   [Webster 1913 Suppl.]