(biol.), the output of the embryos of oviparious
animals (for example, insects, birds, mn. of fishes, amphibious and
other.) from the ovular shells. Depending on composition
and structures of ovular shells the methods v. are different: by
means of the partial over-boiling of shells by the ferments, which are
separated by the special glands of embryo - Vol. n. by glands v.;
via the mech. break of shells by the muscular efforts of embryo
or with the aid of the special adaptations: horny teeth,
protuberances, etc., and also in that and other manner in different
combinations. V. is achieved at the different, characteristic
for each form animal stages of development (for example, at the stage of blastula - in sea urchin or
at the stage of the beginning of active nourishment - in some bony
fishes). See also Yaytserozhdeniye.
