[ˏkinә'dʒenәsis]
n.
[生物]新性发生

[ noun ]
introduction during embryonic development of characters or structure not present in the earlier evolutionary history of the strain or species (such as the addition of the placenta in mammalian evolution)
<noun.process>

Kenogenesis \Ken`o*gen"e*sis\, n. [Gr. ? new + E. genesis.]
(Biol.)
Modified evolution, in which nonprimitive characters make
their appearance in consequence of a secondary adaptation of
the embryo to the peculiar conditions of its environment; --
distinguished from {palingenesis}. [Written also
{cenogenesis} and {c[ae]nogenesis}.]

cenogenesis \cen`o*gen"e*sis\ n. [Gr. ? new + E. genesis.]
(Biol.)
The introduction during embryonic development of characters
or structure not present in the earlier evolutionary history
of the strain or species (as addition of the placenta in
mammalian evolution); a modified evolution, in which
nonprimitive characters make their appearance in consequence
of a secondary adaptation of the embryo to the peculiar
conditions of its environment; -- distinguished from
{palingenesis}. [Also spelled {caenogenesis} and formerly
{kenogenesis}.]
[WordNet 1.5 + 1913 Webster]