The Collaborative International Dictionary of English v.0.48:

Ontogenesis \On`to*gen"e*sis\, Ontogeny \On*tog"e*ny\, n. [See
   Ontology, and Genesis.] (Biol.)
   The history of the individual development of an organism; the
   sequence of events involved in the development of an
   organism; the history of the evolution of the germ; the
   development of an individual organism, -- in distinction from
   phylogeny, or evolution of the tribe. Called also
   henogenesis, henogeny.

   Syn: growth, growing, maturation, development.
        [1913 Webster]