100 A MANUAL OF MENDELISM 



Numbers of Weeks 



Total 

 1 2 3 4 5 6 7 8 9 10 11 12 13 Eggs Total 

 Numbers during for the 



of Hens Eggs laid per week Winter Year 



48 225447665 41 200 



235 — 4 6 5 5 6 5 5 5 5 5 5 7 63 199 



50 — 164546444544 51 203 



158 5 5 5 5 4 5 5 4 5 4 5 5 4 62 202 



53 3557665567 55 218 



51 36466556557 58 209 



9 6555545454554 62 209 



176 6 6 6 5 5 5 5 5 5 5 4 6 64 208 



58 124344 18 96 



163 — 183331 332 22 99 



204 25661— 20 92 



131 244 10 98 



43 5575 22 93 



172 24—443 17 98 



78 556 16 96 



253 •—265583433 34 98 



57 111 — 13 7 43 



105 49 



149 3 3 43 



87 43 



173 60 



170 39 



155 50 



77 56 



The outstanding feature of the ten years' experience 

 at Orono is that, though they may carry it, hens cannot 

 transmit the factor for prohfic egg-laying to their 

 daughters. The factor for femaleness must therefore 

 be coupled with a factor for poor egg-laying which is 

 recessive to a prolific factor transmitted to hens by 

 their fathers. If the tied factor were a dominant the 

 daughters of all good hens would be good layers. Thus, 

 if we call these factors X and x, the following constitu- 

 tions are possible : 



