164 CLASS: RHIZOPODA 



an alternation of generations (Fig. 74). Thus, in Polystomella crispa, 

 a many-chambered shelled form studied by Lister (1895) and Schaudinn 









u ^ 



^ 



>1 



Fig. 74. — Stages in the Life-Cycle of Polystomella crispa ( x ca. 70). (After 



Lang, 190L) 



A. Young megalospheric individual with three chambers. 



B. Fully-grown megalospheric individual. 



C. Megalospheric individual in process of formation of flagellated spores. 



D. Flcigellated spore more highly magnified. E. Fully -grown microspheric individual. 

 F. Microspheric individual in jirocess of formation of daughter amoeboid forms which become 



megalospheric forms. 

 1-3, nuclei of various sizes; 4, fragmenting nucleus; 5, chromatin granules. 



(1895), the individual (microspheric form) becomes multinucleate, and 

 then gives rise to a number of daughter amoeboid forms which escape 

 from the shell (Fig. 74, E and F). Each of these forms a relatively large 



