150 GARY N. CALKINS 



The Q. series, coming from the I series in the 316th generation^ 

 has been queer from the start, dividing only twenty-three times 

 in thirty-three days, and it will soon die out. The exceptional 

 history of this series is probably due to faulty reorganization 

 after conjugation, for the nuclear complex is quite abnormal. 

 If this result is due to the age of the parent series at the time of 

 conjugation, the history of the Q series is an interesting contra- 

 diction to that of the J series where the parent series was rela- 

 tively even older at the time of conjugation. Defective reor- 

 ganization is possible after any conjugation, but the chances of 

 such defective reorganization are probably greater with increasing 

 age of the parent. 



While the several series described above were all derived from 

 one ancestral protoplasm of the A series, two other series, B and 

 G, came from a different source. The B series was started from 

 an encysted Uroleptus mobilis which had encysted in 'wild' 

 stock before the A series was started. It emerged from the cyst 

 on January 25, 1918, and lived until October 9th, dividing 258 

 times between January 25th and September 1st, or 11.8 di- 

 visions in ten days on the average. Many epidemics of conju- 

 gation occurred, but only one ex-conjugant was isolated. This 

 one formed the G series, the B series being in the 115th generation 

 at the time. The same resultant renewal of vitality and con- 

 tinued life of the filial series was observed as with the A proto- 

 plasm, the G series starting with an optimum division rate of 

 18.06 in ten days for the first sixty days, running through 291 

 generations and dying out January 4, 1919. 



3. Does reorganization during encystment {'endomixis' or partheno- 

 genesis) restore waning vitality to full metabolic vigor? 



Unfortunately, I have insufficient data to draw positive con- 

 clusions on this subject. Only two series, B and M, were de- 

 rived from cysts, and of these only the M series is pedigreed. 

 This series was started on November 18th from a cyst that was- 

 formed by an individual of the F series in its 45th generation, 

 on April 27, 1918, and remained encysted for six months. In 



