INHERITANCE IN ABNORMALITIES 



417 



bottle cultures, or discarded. In a number of the charts the second figure is 

 omitted since the selection was the same on every date, one animal of a particu- 

 lar kind being always chosen. When both normals and abnormals are present 

 in a single line (Chart 2) the kind which are entirely discarded are placed above, 

 the kind from which one is chosen is placed below, each with its number. D 

 means that on that date that line died out. Chart 1 therefore reads: On Decem- 

 ber 2 the normal exconjugant was isolated; Decembers, it had divided to form 

 four normals, all of which were kept; December 7, these had divided into eight 

 normals, two of which were kept; these two had divided on December 9 to eight 

 normals, one of which was kept; December 11, this one had given rise to four 

 normals, one of which was kept; December 13, this one had given rise to two 

 abnormals, both of which were kept, and to eight normals, one of which was 

 kept; December 15, the normal had divided to form four, one of which was kept, 

 and the two abnormals, neither of which had divided, were both kept; Decem- 

 ber 17, the normal line was discontinued entirely, one of the abnormal had 

 died, and the other was kept and gave rise by repeated divisions to all the later 

 individuals belonging to Race C. 



Race C therefore appeared to be entirely normal for eleven 

 days after conjugation, at the end of that time producing two 

 abnormals, one of which was double, the other small and de- 

 formed. This small one gave rise to all the later 4681 observed 

 individuals of this race, comprising 303 generations. In 34 lines 

 of this race a continuous selection of normals was made, in one 

 case for 32 da^^s and 24 generations. The data from these lines 

 is given in table 5. Their character was not changed in any 

 way by this selection; the average proportion of abnormality for 

 these 34 lines is only 2 per cent less than that of the race as a 

 whole (table 3). In one line only normals were produced for as 

 long as six days, the line at the end of that time again producing 

 abnormals. The history of this line with a few of the others 

 is given in chart 2. In every case one normal was selected each 



TABLE 5 

 Data from the 34 normal-selected lines of Race C 



