Definition of gemmation:
The Hydra, when it has reached a certain bulk, puts forth from its surface a bud which, growing and gradually assuming the form of the parent, finally becomes detached; and by this process of gemmation the creature peoples the adjacent water with others like itself.- "Essays: Scientific, Political, & Speculative, Vol. I", Herbert Spencer.
- "The Romance of Natural History, Second Series", Philip Henry Gosse.
The latter is one of the numerous species of aphis which begins its attack in the winged state, and after producing wingless green lice in abundance- which further increase by the process known as " gemmation"- reappears with wings in the final generation of the lice, and hibernates in readiness for its visitation in the spring next year.- "Grain and Chaff from an English Manor", Arthur H. Savory.