StralnL l^ 

 " H 9\. 



\ 101(A 172 ) C?5 

 /125{a 150) SSS' 

 . K 43/ 

 . E 18 



Fig. 1 Pedigrees of the rats used. Parents shown in the form of fractions; 

 males above the line, females, below. 'Bro.' indicates that the father was a 

 brother of the mother. Within each strain all the rats in the column at the right 

 (those discussed herein) came from a single pair of great-grandparents, which 

 were themselves brother and sister. Rats marked (F) are called 'failures,' 

 meaning that they had one or more incomplete trials; those marked 'A' were 

 treated with alcohol; the numbers in parentheses tell how many days of the 

 rats' treatment could have influenced the offspring. One pair of rats in each 

 strain were given alcohol till they were dead drunk once a day; pair 101 /125 in 

 strain L was given a light dose, measured by the time of exposure (ninety min- 

 utes) which appeared to cause no intoxication. 



212 



