MORPHOLOGY 43 



nucleate forms, or from the zone between the ectoplasm and endo- 

 plasm (Fig. 6). Although semipermanent in structure, the axial rod 

 is easily absorbed and reformed. In the genera of Heliozoa, not 



. \ M 1 A ." 'K I'' 



' '7' 



r- 





Fig. 5. Pseudopodia of Elphidiuni strigilata, X about 50 

 (Schulze from Kiihn). 



mentioned above and in numerous radiolarians, the radiating fila- 

 mentous pseudopodia are so extremely delicate that it is difficult to 

 determine whether an axial rod exists in each or not, although they 

 resemble axopodia in general appearance. 



There is no sharp demarcation between the four types of pseudo- 



