GENETIC STUDIES OF RABBITS AND RATS. 33 



TABLE 12. Correlation of ear-length with weight. 



Mean ear-length, 105.350.43. S. D. ear-length, 3.860.10. 



Mean weight, 2 14. 15 16.8. S. D. weight, 448.6 11. 9. r, 0.830 0.011. 



TABLE 13. Correlation of ear-length with skull-length. 



Mean ear-length, 105.45 0.42. S. D. ear-length, 11. 46 0.28. 



Mean skull-length, 73.030.16. S. D. skull-length, 4.420.11. r, 0.8360.011. 



