The nucleus has to take care of the inheritance of the heritable characters, while the surrounding cytoplasm is concerned with accommodation or adaptation to the environment.

Mental differences between the lowest men and the animals are less than those between the lowest and the highest man.

Civilization and the life of nations are governed by the same laws as prevail throughout nature and organic life.

By ecology we understand the total science of the connections of the organism to the surrounding external world.

Ontogeny re-capitulates phylogeny.

I established the opposite view, that this history of the embryo (ontogeny) must be completed by a second, equally valuable, and closely connected branch of thought - the history of race (phylogeny). Both of these branches of evolutionary science, are, in my opinion, in the closest causal connection; this arises from the reciprocal action of the laws of heredity and adaptation... 'ontogenesis is a brief and rapid recapitulation of phylogenesis, determined by the physiological functions of heredity (generation) and adaptation (maintenance).

Man is not above nature, but in nature.