VirALITY 



501 



vulgaris as a part of a very complex life cycle. In both of these 

 testate rhizopods the nuclei of the gametes are derived from chro- 

 midia formed in the gametocytes while the cell bodies are formed 

 by multiple division of the protoplasm. In Radiolaria according 



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Fig. 209. — Actinophrys sol, maturation and copulation of gametes. 1, section of 

 individual prior to fertilization; 2, 3, division of nucleus and cell to form two gameto- 

 cytes; 4, 5, 6, first meiotic di\'ision of the two gametocytes; 7, 8, 9, second meiotic 

 division and formation of gametes; 10, differentiation of the gametes; 11, 12, fusion 

 of cell bodies and nuclei. (After B§laf .) 



