218 PROTISTS AND DISEASE 



and called either plastogamy or plasmogamy, is illustrated 

 in 15. Several Arcellae join pseudopodia, protoplasmic 

 currents are interchanged ; the animals then separate. 



The above brief survey of the salient life-processes in 

 one of the Rhizopoda Lobosa suffices to show that the 

 chromldial phases are essential, and that the sexual repro- 

 duction is confined to them. If the summer phases of the 

 organism alone had been studied the most important part 

 of its life-history would be unknown. 



If we examine an Arcella in the stage shown in Fig. 60 : 

 5, separate granules stained like chromatin are recognisable 

 in the cytoplasm. The term " chromidiosomes " has been 

 applied to such granules. 



The cell-theory adjusted to facts. As depicted by different 

 observers Arcella vulgaris passes through two non-nucleated 

 phases ; namely, that immediately preceding the condition 

 shown in Fig. 61, 8 and 9, and that shown at 10. These 

 two may be considered as modifications of the same phase. 



The distributed nuclear matter seen in some Ciliata 

 such as Chaenia teres, and in Cyanophyceae, such as Chroo- 

 coccus turgidus, may, I think, be regarded as true nuclei. 

 The Chroococcaceae were regarded as non-nucleated by 

 Haeckel. It is different with the chromidial phases of 

 organisms such as Arcella and Sorosphaera (Chapter VII) : 

 in these new nuclei arise, nqt by simple transverse division, 

 but by confluence of chromidial granules. 



We may infer from the unqualified acceptance of Flem. 



