50 



BULLETIN 1121, U. S. DEPARTMENT OF AGRICULTURE. 



Table 14. 



-Data on the fertility in the various inbreeding and crossbreeding experiments, 

 1916-1919. 





Size of litter. 



Num- 

 ber of 

 mating 

 years. 



Num- 

 ber of 

 litters. 



Num- 

 ber of 

 young. 



Aver- 

 age 

 size of 

 Utter. 



Aver- 

 age 



litters 

 per 



year. 



Aver- 

 age 



young 

 per 



year. 



Aver- 



Experiment. 



1 



2 



3 



4 



5 



6 



7 



young 



raised 



per 



year. 



2 



87 

 45 

 60 

 64 

 39 

 119 



187 

 115 



81 

 120 



53 

 210 



133 



85 

 63 



108 

 51 



140 



32 

 33 

 18 

 40 

 17 

 44 



2 

 12 

 1 

 9 

 . 2 

 7 







119.3 

 90.7 

 67.8 

 94.9 

 56.3 



194.5 



441 

 293 

 223 

 341 

 163 

 520 



998 

 740 

 488 

 833 

 382 

 1,170 



2.26 

 2.53 

 2.19 

 2.44 

 2.34 

 2.25 



3.70 

 3.23 

 3.29 

 3.59 

 2.90 

 2.67 



8.37 

 8.16 

 7.20 

 8.78 

 6.79 

 6.01 



5.00 



13 



3 



.... 



4.30 



32 



3.91 



35 







5.11 



39 



1 





3.39 



Other 



2.80 











Inbred 



CO 



414 

 134 

 31 

 19 

 42 

 SO 

 13 



766 

 235 

 57 

 41 

 69 

 77 

 31 



580 

 157 

 46 

 57 

 82 

 73 

 19 



184 

 51 

 23 

 44 

 35 

 39 

 10 



33 

 11 



7 

 15 



9 

 10 



2 



4 





623.5 

 183.2 

 39.4 

 48.2 

 54.3 

 .57.4 

 17.6 



1,981 

 588 

 164 

 184 

 238 

 249 

 75 



4,611 

 1,334 

 410 

 571 

 617 

 629 

 182 



2.33 

 2.27 

 2.50 

 3.10 

 2.59 

 2.53 

 2.43 



3.18 

 3.21 

 4.16 

 3.82 

 4.38 

 4.34 

 4.26 



7.40 

 7.28 

 10.41 

 11.85 

 11.36 

 10.96 

 10.34 



3.96 



4.48 



CA 







7.99 



AC 



8 

 1 





9.02 



CC 



7.61 



CI 



7.46 



C2 .. .. 







7.10 











CL 



21 

 32 



81 



40 

 64 



188 



44 

 56 



212 



22 

 41 



78 



6 

 13 



21 



5 



4 





33.8 



47.4 



138 

 210 



381 

 581 



2.76 

 2.77 



4.08 

 4.43 



11.27 

 12.26 



8.31 



CG 



8.16 







B 



7 



1 



1.59. 6 



588 



1,559 



2.65 



3.68 



9.77 



6.71 







Table 15. — Percentage horn alive. 



i Average in litters af each size, the combined average, and the index (litters of 1, 2, 3, and 4 weighted 1, 3, 3, 

 and 1, respectively). Inbreeding and crossbreeding experiments, 1916-1919.] 



Experiment. 



Size of litter. 



Total. 



Index. 



1 



2 



3 



4 



5 



6 



7 



■2 



69.0 



82.2 

 86.7 

 70.3 

 87.2 

 82.4 



78.9 

 81.7 

 90.1 

 89.6 

 85.8 

 80.2 



77.4 

 77.6 

 76.2 

 78.7 

 81.0 

 75.5 



67.2 

 65.2 

 61.1 

 63.1 

 60.3 

 53.4 



30.0 

 48.3 

 0.0 

 42.2 

 90.0 

 31.4 







75.5 

 72.7 

 79.1 

 76.2 

 79.8 

 73.2 



75.6 



13 



0.0 





78.2 



52 



80.8 



35 







79.8 



39 



100.0 





81.0 



Other 



75.4 











Inbred 



78.7 

 85.1 

 87.1 

 73.7 

 85.7 

 90.0 

 92.3 

 95.2 

 84.4 



83.0 

 87.1 

 86.8 

 92.7 

 86.2 

 93.5 

 90.3 

 96.2 

 89.8 



77.4 

 75.6 

 86.2 

 91.2 

 89.4 

 84.9 

 78.9 

 92.4 

 89.3 



61.4 

 63.2 

 80.4 

 90.3 

 77.9 

 80.8 

 85.0 

 69.3 

 73.8 



43.0 

 52.7 

 71.4 

 86.7 

 71.1 

 70.0 

 90.0 

 73.3 

 60.0 



25.0 





75.3 



77.7 

 83.9 

 88.4 

 84.1 

 85.2 

 85.7 

 84.3 

 80.4 



77.7 



CO : 



79.5 



CA 







85.8 



AC 



72.9 

 50.0 





89.5 



CC 



86.3 



CI 



88.2 



C2 







85.6 



CL 



63.3 

 62.5 





91.3 



CG... 



86.9 







B 



84.0 



91.0 



85.4 



81.1 



81.0 



52.4 



0.0 



84.2 



86.8 







