EFFECTS OF REORGANIZATION 



349 



results of conjugation between individuals of each set. In the first 

 set the high division-rate would appear to be inherited ; in the third 

 set the low division-rate in most cases would appear to be inherited 

 but such series invariably die. The real test is shown by conjugation 



Fig. 168. — Variations in 

 caudatu 



the progeny of a single ex-eonjugant of Paramecium 

 in. (After Calkins and Gregory.) 



in the second set which results in optimum division-rates. In such 

 sets of progeny, as shown above, the differences in vitality of the 

 offspring through conjugation are due to differences in vitality of 

 the parent. With low vitality of offspring from old parents it might 



