STUDY OF SELECTIONS FOR SIZE, SHAPE, AND COLOR OF HENS' EGGS 225 



played a character between the two. In most instances in which the sire 

 and the dam were both of the same extreme character, the progeny dis- 

 played a character nearer to normal than either of the parents. In the 

 case of small size, however, this tendency was reversed, and the 

 character for the progeny from two small parents was of a still smaller 

 type. In this case it is probable that tho effect of the size of body was 

 to limit the size of the eggs (Benjamin, 1914). 



The relative effect of the sire and the dam is shown clearly in figures 

 15 to 17. In figure 15 it is seen that small size is predominant over large 

 size. The sire will transmit small size to the progeny much more strongly 

 than large size. In the instance in which both parents are large, only 

 58.6 per cent of the progeny possess the "large" character; but when 



58.6% 



Large sire Small sire Large sire Small sre 



Small dam Large dam Large dam Small dam 



FlG. 15. RELATION OF PROGENY SIZE CHARACTERS TO SIRE AND DAM 



The white area in each case designates the proportion of progeny showing the same character as that of 



the sire 



both parents are small, 81.9 per cent of the progeny possess the "small" 

 character. The two parents appear here to have about equally strong 

 influence in transmitting the "small" character. The predominance of 

 the small size may be due to the additional physiological factors involved 

 by the size of the dam's body restricting the size of egg which can possibly 

 be produced, without regard to any inherited tendencies. A hen with 

 a large body can produce a small egg, but a hen with a small body cannot 

 so readily produce a large egg. 



The question of the inheritance of egg shape may not be entirely free 

 from the physiological complications involved in the study of egg size. 

 This opinion is borne out by figure 16. The dam seems to have nearly 

 60 per cent of the influence on the progeny. The fact that the two long 

 parents have a somewhat higher percentage of the progeny following 

 their type than do the two round parents, would lead to the theory that 



