122 OPALINA LESS. 



(compare Fig. 10, p. 64, with Fig. 24, c) : the chromatin 



n u 



FlG. 24. Opalina raiiaru/n. 



A, living specimen, surface view, showing longitudinal rows of cilia. 



B, the same, stained, showing numerous nuclei (nit) in various stages 

 of division. 



c, i 6, stages in nuclear division. 



D, longitudinal fission. 



E, transverse fission. 



F, the same in a specimen reduced in size by repeated division. 



G, final product of successive divisions. 

 H, encysted form. 



I, uninucleate form produced from cyst. 



K, the same after multiplication of the nucleus has begun. 



( A _ c , after Pfitzner ; D K, from Saville Kent, after Zeller.) 



breaks up (c, 2), a spindle is formed with the chromosomes 

 across its equator (3), the chromosomes pass to the poles of 



