INHERITANCE IN ABNORMALITIES 399 



Figures 5 and 6 give pedigrees of two of these transiently 

 abnormal races, numbers 14a and 102a, which are fairly typical 

 of this group. Race 14a (fig. 5) was kept for thirteen days. 

 During that time it divided 17 times, giving an average of 1.13 

 divisions a day. It showed no abnormalities until December 

 11 (nine days after conjugation), when the three individuals 

 which had arisen from the apparently normal animals selected 

 on December 9 were, one large and very abnormal, one small 

 and abnormal, and the third small and almost normal in appear- 

 ance. The large one died after having divided once. The two 

 small ones had divided to form four normal individuals on 

 December 13, and on December 15 had given rise to eight per- 

 fectly normal animals which were then discarded. 



Race 102a (fig. 6) divided very slowly at first, averaging 0.5 

 divisions a day. The average division a day for the whole time 

 the race was kept was 0.8, the animals dividing much more 

 rapidly toward the last. This exconjugant showed no signs of 

 being abnormal until December 11, when the three forms pres- 

 ent were very abnormal, two being doubles and one a very 

 much swollen individual. One of the double forms moved in 

 a circle so swiftly that it could not be drawn. Both of the 

 double forms died without dividing; the large swollen one gave 

 rise to a perfectly normal race which was discarded on December 

 17. 



2. In the second class of abnormal races are those which 

 persistently produced abnormal individuals throughout their 

 history. There were 9 such races in Experiment 1 and 88 in 

 Experiment 2. They differed greatly in the proportions of 

 abnormals produced, varying from races 100 per cent abnormal 

 to those but 3 per cent abnormal. The pertinent data for these 

 97 persistently abnormal races is given in table 3. 



In many of these persistently abnormal races individuals 

 appeared which were normal in form. But these if propagated 

 eventually produced abnormals. Further details as to this will 

 be given in our section on the effects of selection. 



Figures 7 and 8 give pedigrees of two of the short-lived races 

 of this group, 39b and 40b, which show the typically persistent 



