254 



BIOLOGY OF THE LABORATORY MOUSE 



inbred dBP^i animals (F2 from the cross dba 9 X C57 black cf )• This is 

 the dBF2 generation. 



Table 3 

 dB F2 Generation 



The incidence in all animals which lived as long as or beyond the age 

 of the animal in which a tumor first appeared is 35.54 per cent. 



