EFFECTS OF INBREEDING AND CROSSBREEDING. 5d 
[aBLE 24.—Number of young born during successive $-month periods, 1916-1919. 
Inbreeding and crossbreeding experiments. 
1916 | 1917 1918 | 1919 
a in ce oe ee Total. 
7-9 10-12 1-3 | 4-6 | 7-9 110-12) 1-3 4-6 7-9 10-12 1-3 | 4-6 | 7-9 |10-12 
| | 
47 | 59 | 36| 47) 49 46/ 56/ 67/100 91/ 82| 58 998 
37| 18| 34] 41| 24/ 23] 21] 37] 58| 62| 79| 60 740 
WA} 2] 17| 33| 2) 2] 2] 15] 2) 43] 39] 38 488 
64| 41/ 33/ 43/ 41/ 41. 39! 53| 45| 54. 60 | 71 | 73 833 
P 2a SS) at a ae 2 | at et “a7 382 
TS OE y OU By Paglia gg ae eee 
a a a ee ee ee 
| 299 | 261 S 232 189 164 Ts 175 | 254 273 | 283 |-256 
100 | 118 | 140 | 137 | 174| 97/| 80 63, 56| 57] 58 64] 77] 81 
r £7 77 wy )- 129} | 14] 30] 38 85/116! 63 
PR ve Pg RO) gs ge ge loge | 44| 68 134 | 102 | 115 
28 | 51|128| 90| 95| 68) 57] 48) 34 .....).....)..... 
30} 53| 70] 89! 91/| 73| 64] 66| 29 29] 13]..... 
CPS NS BE SA Se 5| 11| 18] 30| 12) 22| 26] 28| 18] 12| 2 
LOSS REP 28 ge Sel a ee |......1 2] 27] 18] 25| 32] 50} 90) 83] 54 
S2eR, SL mee J-----[-----|-----|-----|-----| 21 | 49 | 46] 43] 49} 105 | 11) 82| 7% 
86/139 115 105/110/106| 93 87 71| 79 | 79 | 123 94 | 82 | 75 | 1, 559 
TaBLE 25.—Number of young born alive during successive 3-month periods, 1916-1919. 
Inbreeding and crossbreeding experiments. 
| 1916 | 1917 1918 | 
Experi- | 
ment. | | | | | 
1-3 | 46 7-9 10-12 1-3 | 46 | 7-9 10-12 1-3 4-6 | 7-9 10-12 1-3 
{ | 
poh 29| 49) 56) 42 26| 43| 42 34/| 44| 59 79 
13.......| 38] 35] 62] 36 | 21] 28] 21 | 11] 18] 30] 38 
32.......| 27] 20] 36| 27 17| 25} 16 19] 22] 15] 19] 
35..-..-.| 47] 36| 48] 45 33 | 35) 39) 19| 43] 37) 45 
39.......| 35| 32! 39| 28 13} 19 | 12/13} 7| 4! 15 
Other...| 156 | 108 | 134 | 136 72| 40| 22) 13) 8| 7|.....|-----|----- 
Inbred... 332 | 280 375 | 314 182 190 | 152 109 | 142 | 152 196 
SE ee 22| 77| 71 135 | 86] 67| 42| 34| 47| 50| 
yas GRE es eS ee is| “a| ww! <9) 42] Sr) el 
Be ee Be ee Raa ae | 5| 24/ 13) 20] 2] 42/ 65 
Le Bae 28 2| 13 | 102! 78| 77 58] 49| 46| 27 
eaee Bolle pion ee 17 | 62| 78! 80) 66] 52] 51| 29 
7 ELS SRS cee Bar 141 | 12] 26] 11] 18| 26| 24 
ee eS BS a as he a Bee | 21 16| 13] 19] 30; 4 
2. ES ES Se Rs a a Ea aes | 20] 32) 34] 28] 48) 79 
