n. [ Mono- + genesis. ] 1. Oneness of origin; esp. (Biol.), development of all beings in the universe from a single cell; -- opposed to polygenesis. Called also monism. Dana. Haeckel. [ 1913 Webster ]

2. (Biol.) That form of reproduction which requires but one parent, as in reproduction by fission or in the formation of buds, etc., which drop off and form new individuals; asexual reproduction. Haeckel. [ 1913 Webster ]

3. (Biol.) The direct development of an embryo, without metamorphosis, into an organism similar to the parent organism; -- opposed to metagenesis. E. van Beneden. [ 1913 Webster ]