Meanings of exogens in English

You must know before anybody else how the exogens are to be completely divided.

Saponin is found in endogens and exogens.

Take the characters of exogens as distinct from endogens; even under ordinary circumstances, no absolute distinction can be drawn between them.

Grass-seedlings seem to suffer much less than exogens...

Possible Cause of sudden late Appearance of Exogens.

Dicotyledons (called also Exogens).