HEREDITY OF WILDNESS AND SAVAGENESS IN MICE 



23 



individuals possessing a grade of wildness and savageness or 

 tameness and non-savageness equal to that of the parental 

 generation. The second section of the table indicates that the 

 degree of wildness and savageness of the F2's varies about the 

 same intermediate grade and that this variability is also in 

 accordance with Mendelian expectation in being greater than 

 that of the Fi's. The number of cases studied, however, is 

 scarcely large enough to give sufhcient basis for an estimate of 

 the number of factors involved. 



B. Effect of age, frequency and 7iumber of tests on the lowering 

 of the grade of wildness and savageness in successive 



tests 



In table 12 are given the average results of the successive 

 tests of all hybrids of the three generations that received the 

 regular tests, and also the amount of difference in the grades 

 of wildness and savageness in the successive tests. 



It is readily seen by this table that there is a fairly gradual 

 lessening in the grades of wildness and savageness from the 

 first test to the last. The greatest amount of decrease in the 

 grade of wildness occurs between the second and third tests. 

 With this exception the amount of decrease is greatest between 

 the first and second tests and gradually diminishes with the 

 successive tests. 



In the attempt to determine the cause or causes for this 

 lowering of the grades of wildness and savageness with the 

 repetition of the tests, three different methods were used as 

 follows : 



1. Individuals were allowed to remain untested, unnumbered, 

 and without being handled, in the cage in which they were 



