Professor Haeckel in his "Generelle Morphologie" and in another works, has recently brought his great knowledge and abilities to bear on what he calls phylogeny, or the lines of descent of all organic beings.
Häeckel irakasleak bere ezagutza eta gaitasun handia erabili du, Generalle Morphologie eta beste zenbait lanetan, filogenia deitu dion horretan, hau da, izaki organiko guztien ondorengotza lerroetan.