PERIODIC REORGANIZATION OF P. CAHDATUM 



69 



during this time the culture attained the 207th generation. 

 The process of reorganization occurred at about the 18th. 136th 

 and 203d generation (table 1). Line III which had successfully 

 undergone the process at the 136th generation lived to the 192d 

 generation, just at the onset of the next reorganization period. 

 That the phenomenon was imminent is e\'ident also from Sub- 

 line III fa, in which it appeared at the 202d generation. From 



Sh'jwing th 



e occurrence 



TABLE 1 



' (if the reurgan.izatii 



II process ill Culture Y 



PERIODS = 



I. 



II. 



III. 



Ill a.* 

 Ill b. 

 Ill c. 

 Ill d. 

 Ill e. 

 Ill f. 

 Ill fa. 

 Ill fb. 



III g. 

 IV. 



IV a. 

 IV aa. 

 IV ab. 

 IV ac. 



1-59. 



1 107 



1-192 

 120-130 

 143 163 

 161-163, 

 161-165 

 165-169, 

 167-184. 

 169-203. 

 169-206. 

 192-207 



1-89 . 



85-115. 



93-143. 



108-114. 



120-137. 



HEM.'lRKS 



Died 



Died 



Died 



Killed ill descending phase 



Died 



Killed 



Killed 



Died 



Killed 



Killed in descending phase 



Died 



Died 



Killed 



Killed 



Killed in ascending phase 



Died 



Killed in descending phase 



* Designated Line 2 in our 1914 (III) paper. 



a close analysis of the division rate, and of the longevity of the 

 component lines of Culture Y (table 2) it is apparent that of 4 

 lines and 13 sublines, 13 did not undergo a division for at least 

 twenty-four hours, and in some cases for forty-eight hours, be- 

 fore their death. Death occurred in these lines either 'naturally' 

 or as a result of the animals being killed for study since they were 

 dividing slowly. Two lines or sublines died naturally without 

 a lowering of the division rate, ten were purposely killed and 

 four died after a lowering of the division rate. Sub-line III a. 



