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THE AMERICAN NATURALIST 



[Vol. L 



Fig. 10. Descent of a small family of mice showing good records. 



In Table V are given the total records for the isolated 

 cases, which complete all the individuals tested. Here 

 again the relative inferiority of the yellow mice may he 

 noted. 



Summary 



1. Albino and colored mice can be used to advantage for 

 laboratory work on animal behavior. 



2. The type of maze used seems well adapted for this 

 kind of work. 



3. There is a marked difference in individual behavior. 



4. There appears to be a resemblance among individ- 

 uals of the same litter. 



5. There appears to be a considerable difference among 

 different strains. 



6. The sex differences, if any, are very slight. 



