Natural Selection.—Survival of the Fittest in the struggle for existence. For a full account of the process see Darwin and after Darwin, p. 251 et seq.
Neo-Darwinians.—Those who believe that Natural Selection has been the only modifying influence in the evolution of species, and that the material for its action has been only plasmogenetic characters (q. v.).
Neo-Lamarckians.—Those who hold that organic evolution has been effected solely by means of the occurrence and preservation (inheritance) of somatogenetic characters (q. v.).
Nuclear Thread or Loops.—See Chromatin threads.
Nucleo-plasm.—See pp. 30 and 32.
Nucleus.—See Cell nucleus.
Nutritive congenital characters.—See p. 64.
Ontogenetic grades.—See p. 35.
Ontogeny.—The life history of the individual, as distinguished from the ancestral history of the race (Phylogeny).
Ova.—Eggs—the product of the female reproductive gland (ovary or ovarium).