54 INDIVIDUAL DIFFERENCES AND FAMILY RESEMBLANCES 



(UNKNOWN) 



N0.32Y No33Y No3*Y No 35Y No.36Y No.37Y 



FIG 15. Descent of a Family of Mice consisting mostly of Yellow Individuals. 



and 18 seconds, while one gave a record of 71 seconds; two females 

 also made good records, and one an average record. None of the 

 mice in this litter made records as low as either of their parents. 

 The second litter of No. 116 X No. 121 was rather large, composed of 

 ten mice, but three of the seven males died before their records were 

 completed (see Table III. for records of Nos. 180, 183 and 185), and 

 one male, No. 184, died before the tests began. Three of the males 

 and one female that completed their records made fairly quick aver- 

 ages, while two females gave time averages of 98 and 83 seconds. 

 The family average amounted to 53 P.E. 9.6 seconds. When No. 

 116 was mated with No. 120, whose average was 11 seconds, a sixth 

 generation litter of four mice resulted ; two were males and died be- 

 fore their records were completed (see Table III. for records of 145 

 and 146), and one female, No. 147, gave the very poor record of 210 

 seconds. This was the female that failed completely in all the maze 



