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TEXTBOOK OF ZOOLOGY 



ranged in a line form a linear one, and colonies of irregular arrange- 

 ment are spoken of as gregaloid. Tlie difference between these 

 colonial Protozoa and simple Metazoa is a difference in the relation- 

 ship of single cells to the group as a whole and not a simple difference 



B 



Fig. 31. — Volvox. A, Mature colony containing- several daughter colonies. B, 

 Formation of daughter colony by development of a parthenogonidium. (From 

 White, General Biology j The C. V. Mosby Company.) 



in numbers of cells. In the colony each cell is an independent or 

 almost independent individual so far as the functions of living are 

 concerned. In the structure of Metazoa the cells are specialized and 



