PLATE 2 



EXPLANATION OF FIGURES 



13 Interchange of micronut-loi in form of minute spheres. (Tliese may be 

 fused nuclei and not pronuclei, in which case the two smaller nuclei are 'reduc- 

 lion nuclei.') From section, X 1000. 



14 Interchange of micronuclei. Four pronuclei in the region of interchange. 

 Seven reduction nuclei in individual on right, four on left. From section, X 

 1000. 



15 Union of pronuclei. Three reduction nuclei in same vicinity in each cell. 

 From section, X 1000. 



16 Conjugating individuals. The syncaryon in each is swollen and the macro- 

 nuclei are undergoing fragmentation. From section, X 500. 



17 Early stage in conjugation, with the first changes of the micronuclei. 

 Method of fusion and overlapping of the adoral zone distinctly shown. From 

 total prei^aration, X 400. 



18 Syncaryon in each cell preparing for the first division. Breaking up of 

 the macronucleus within its capsule. From section, X 1000. 



19 Full mitosis of the syncaryon, first division. From section, X 1000. 



20 Second division of the syncaryon (on left). A third enigmatical body 

 in each cell. From section, X 1000. 



21 Pause after first division of the syncaryon. End stage in the separation 

 of the conjugants. From total preparation, X 400. 



22 Vacuolization of the zone of fusion preparatory to separation. Nuclei 

 in stage of pause. From total preparation, X 400. 



23 Ex-conjugant in same stage as that of figure 21. From total preparation, 

 X400. 



24 Ex-conjugant sliowiug two new macronuclei with central micronuclei. 

 The micronucleus in one has just divided as shown by the connecting strand. 

 From section, X 500. 



25 Ex-conjugant showing three new macronuclei (the fourth is in another 

 section). From section, X 500. 



GOO 



