486 GLOSSARY. 



Zoea-stage. — The earliest stage in the development of many of the 

 higher Crustacea, so called from the name of Zoea applied to these 

 young animals when they were supposed to constitute a peculiar 

 genus. 



Zooids. — In many of the lower animals (such as the Corals Medusae, 

 etc. ) reproduction takes place in two ways, namely, by means of 

 eggs and by a process of budding with or without separation from 

 the parent of the product of the latter, which is often very differ- 

 ent from that of the egg. The individuality of the species is repre- 

 sented by the whole of the form produced between two sexual 

 reproductions; and these forms, which are apparently individual 

 animals, have been called zooids. 



