20 



GENERAL ORGANIZATION OF THE PROTOZOA 



colonies. A gregaloid colony arises by the adventitious union of 

 previously separated cells. Thus, many of the so-called "agglomera- 



FIG. 3 





Uroglena americana, Calkins, a spheroid colony, consisting of monads embedded 



in a gelatinous matrix. 



FIG. 4 



Codosiga cymosa Sav. Kent, an arboroid colony of Choanoflagellates. (After Kent.) 



tions" of spirochetes and trypanosomes are gregaloid colonies brought 

 about by some adverse condition of the environment. A spheroid. 



