290 BIOLOGY OF THE PROTOZOA 



flagelliflt^ and PhalansteriicUe. (\)l()n\- formation is frequent, the 

 spheroid, arboroid and catenoid colonies, however, never attaui to 

 the complexity and differentiation of the phytomastigote colonies. 



Fig. i;:!9.-Arlwroi.l colony of protomonads, Poteriodcndrcn petiolalum. (Original.) 



Somatella formation is frequent in parasitic forms or this may be 

 replaced hx multiple division within a cj^st. Sexual processes have 

 been repeatedlv flescribed but the observations are not convincing 



