ontogenesis

It is naturally no easy matter to trace the ontogenesis of the herd instinct.

Haeckel demonstrates the parallelism between ontogenesis and philogenesis—between the successive forms in the evolution of the embryo and the successive forms of the individual in the evolution of a race.

This exceedingly important larval form, the "gastrula," makes its appearance in the ontogenesis of all tribes of animals.

But ontogenesis would have furnished us with facts no less cogent.

Morphology must be taught as mere descriptive anatomy and systematising, the history of development as mere descriptive ontogenesis.