GLOSSARY. 519 



Whorls. — The circles or spiral lines in which the parts of plants are 



arranged upon the axis of growth. 

 Workers. — See Neuters. 



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 vnth or without separation 

 from the parent of the product of the latter, which is often very 

 different from that of the egg. The individuality of the species 

 is represented by the whole of the form produced between two 

 sexual reproductions; and these forms, which are apparently 

 individual animals, have been called zooids. 



