What's the difference between metagenesis and prothallium?

Metagenesis

Definition:

(n.) The change of form which one animal species undergoes in a series of successively produced individuals, extending from the one developed from the ovum to the final perfected individual. Hence, metagenesis involves the production of sexual individuals by nonsexual means, either directly or through intervening sexless generations. Opposed to monogenesis. See Alternate generation, under Generation.
(n.) Alternation of sexual and asexual or gemmiparous generations; -- in distinction from heterogamy.

Example Sentences:

(1) To test directly the importance of Glu-584 in the catalytic activity of neutral endopeptidase by site-directed metagenesis, we have constructed an expression vector in which the rabbit kidney cDNA encoding the entire neutral endopeptidase sequence is introduced downstream from the SV40 virus early promotor.