PLATE 2 



EXPLANATION OF FIGURES 



7 Culture Y, Line III g, 202d generation, June 7, 1914. Markedly wrinkled 

 niacronucleus and one chromatin body. Part of crescentic stage of micronucleus 

 shown protruding from under the macronucleus. 



8 Culture Y, small tube culture, about the 82d generation, April 1, 1914. 

 Macronucleus broken into several large pieces. Elongated micronucleus, one 

 pole partly devoid of chromatin. 



9 Culture M, Line II, 89th generation, February 19, 1915. Completed 

 fragmentation of macronucleus into two parts. 



10 Culture Y, small tube culture, about the 137th generation, April 22, 1914. 

 Animal with macronucleus breaking into two parts. First 'reduction' micro- 

 nuclear division completed. 



11 Culture M, Line I, 90th generation, February 19, 1915. Macronucleus 

 broken into two pieces from which chromatin is streaming and forming chromatin 

 bodies. Two micronuclei are present, one of which is drawn. The presence 

 of numerous food vacuoles is due to transferrence of this animal to rich hay 

 infusion medium previous to killing. 



12 Culture Y, Line IV, 26th generation, March 2, 1914. Two 'reduction' 

 micronuclei are present. 



8(i 



