42 GENETIC STUDIES OF RABBITS AND RATS. 



Table 32. — Comparative size of the two sexes in the several groups of cross-bred rabbits. 



Group. 



Tibia. 



Males. Females. 



Femur. 



Males. Females. 



Humerus. 



Males. Females. 



Skull-length. 



Males. Females. 



Fi, PXH 

 F2, P XH 

 Fi, HXF 

 Fs, HXF 

 Fi, PXF. 

 F2, P XF . 



Weighted mean*. 

 Per cent greater . . 



93.65 

 90.07 

 100.20 

 97.78 

 96.69 

 94.29 



91.65 

 89.68 

 97.90 

 96.88 

 95.75 

 92.11 



78.78 

 76.45 

 87.95 

 84.90 

 83.52 

 80.87 



77.45 

 75.97 

 86.68 

 84.63 

 83.15 

 79.53 



63.53 

 61.15 

 69.45 

 67.36 

 66.41 

 64.03 



62.20 

 60.73 

 68.26 

 67.33 

 65.93 

 63.88 



70.50 

 69.18 

 79.48 

 76.37 

 75.59 

 73.14 



69.95 

 68.80 

 78.58 

 76.66 

 75.50 

 73.12 



94.72 

 1.58 



93.24 



81.35 

 1.10 



80.46 



64.66 

 0.57 



64.29 



73.42 

 0.16 



73.30 



Group. 



Anterior 

 skull-width. 



Males. Females. 



Posterior 

 skull-width. 



Males. 



S 



Females. 



Ear-length. 



Males. 



Females 



Weight. 



Males. 



Females. 



Fi, PXH. 

 Fj. PXH. 

 Fi, HXF. 

 Fs, HXF. 

 Fi, PXF. 

 F2, PXF. 



Weighted mean" 

 Per centgreaier. 



39.90 

 38.65 

 43.63 

 41.91 

 42.48 

 41.28 



38.65 

 37.94 

 42.36 

 41.38 

 42.13 

 40.32 



40.23 

 38.61 

 43.88 

 42.49 

 42.84 

 41.20 



38.35 

 37.90 

 42.70 

 41.50 

 41.58 

 40.38 



9.54 

 9.25 

 11.45 

 11.50 

 10.91 

 10.69 



9.42 

 9.16 

 11.66 

 11.65 

 10.97 

 10.71 



1,957 

 1,560 

 2,694 

 2,401 

 2,469 

 2,080 



2,005 

 1,704 

 2,886 

 2,531 

 2,545 

 2,176 



41.05 

 2.03 



40.23 



41.21 

 2.46 



40.22 



10.55 



10.58 

 0.20 



2,110 



2,221 

 5.26 



* The weighted means were obtained by counting each male mean the same number of times 

 as each female mean, the nun^ber of individuals assumed for the purpose of the computation 

 to occur in each sex of each gioup being as follows: Fj, PXH, 15; F2, PXH, 30; Fi, HXF, 10; 

 Fj, HXF, 33; Fi, PXF, 15; Fj, PXF, 65. 



