This exceedingly important larval form, the "gastrula," makes its appearance in the ontogenesis of all tribes of animals.
It studies man from two different points of view: his development (ontogenesis), and his variations.
The ontogenesis of any given living organism is a short, condensed recapitulation of its ancestral history or of its phylogenesis.
It is naturally no easy matter to trace the ontogenesis of the herd instinct.
But ontogenesis would have furnished us with facts no less cogent.
It summarises the history of species; ontogenesis, we are told, reproduces phylogenesis.
ontogenesis on·to·gen·e·sis (ŏn'tō-jěn'ĭ-sĭs)
ontogeny on·tog·e·ny (ŏn-tŏj'ə-nē)
The origin and development of an individual organism from embryo to adult. Also called ontogenesis.