64 INHERITANCE, FERTILITY, AND SEX IN PIGEONS. 



The data demonstrate that among these individuals the strongest germs the 

 germs of highest efficiency in the 1 accomplishment of development were produced 

 by the earlier birds of the season. The two individuals from the very first eggs of 

 the season, and those from the last several eggs of the season, were completely or 

 almost completely infertile. Almost completely fertile birds (females) arose from 

 the early season. There appears in these results, moreover, a higher degree of 

 fertility in the females than in the males. The probable bearing of this fact has 

 been already pointed out. The data indicate, therefore, that the low levels of 

 fertility, attained by experimental means late season with overwork are levels 

 which not only influence the sex of offspring as shown elsewhere, but that the func- 

 tion of fertility which is thus forced to new levels tends to propagate itself in 

 inheritance upon such newly formed or enforced levels. 



TABLE 29. 



d 1 215 St. alba 1909-10; G/14/14; 48+ mo. 



cf 412T.orientalis; 6/11/11; 3/15/13; 2l}4 mo. 



9 481T.orientalis; 6/25/11; alive 10/1/14; 40+ mo. 



In summer of 1912 this female was with 9489; winter 1912-13 with brother 412; <? 412 died 3/15/13 

 (unmated). 



St. alba d" 215 given 5/1/13. 

 A. 3/20/13; (cold) (first in life). 



B. 5/14/13; not incubated. 1 E. 6/5/13, from perch and broken. 2 



C. 5/23; not incubated. F. 8/5; from perch and broken. 



D. 6/1; not incubated. G. 8/9-10; from perch and broken. 



A. 1/2/14; not incubated. E. 3/26; no trace development. 



13. 1/27; not incubated. F. 4/11; not incubated. 



C. 3/8; not incubated. G. 5/2; no development. 



D. 3/10; no trace development. H. 5/28; no development. 



d" 715 St. alba; 8/28/13; alive 10/1/14; 13+ mo. 



This male given 6/1G/14, when it was active and fertile. On 7/16 (unmated), removed, and her brother 

 i I-'l) given; no result; cf 421 died 1/1/15. (O. R.) 



1 Advantage was taken of the opportunity here offered to stud3' the size relations of the egg-yolks of a female that laid 

 clutches each of a single <-mj. 



2 The nesting habits of this bird were never normal. Several of her eggs were slightly broken. 



TABLE 30. 



cf St. alba (672); about August, 1912 (from dealer); 4/17/14; 21? mo. 

 9 T. orientalis (429); 8/8/11; alive 10/1/14; 3+ yr. 



A 1. 5/11/13; first in life; shell roughened with calcareous nodules. 

 A 2. 5/12/13; soft shell. 



1) 1. 5/27; from perch; broken. I. 7/26/13 (bird confined) no development. 



B 2. 5/29; not tested. 



J 1. 8/4; no development. 



C. 6/6-7; from perch; broken. j 2. 8/6; no development, 



Ul. 0/14; no development. K 8/13; no development. 



D 2. 6/10; no development. 



L. 8/16 or 17; from perch, broken. 

 K 1. li, L'-J; from perch; broken. 



10 J. 0/24; DO development. M 1- */-':*; '"> development. 



M 2. 8/25; no development. 

 F l. 8/80; no development. 

 I 2. 7/2; no development. N 1- 9/3; no development. 



N 2. 9/5; on ground, no development. 

 G 1. 7/10; from perch; broken. 



G 2. 7/12; no development. O 1- 9/13; no development. 



O 2. 9/15; no development. 

 III. .MX; from perch; broken. 



VII-'. 7/20; white; 714; dead 11/26/13; 4 mo. C da. (O. R.) 



