692 
Journal of Agricultural Research 
Vol. XXXI, No. 7 
The low-weight group contains a slightly larger percentage of 
fertile eggs that hatched than the medium-weight group, while the 
high-weight group contains a percentage of fertne eggs that hatched 
considerably lower than either of the others. This situation is much 
the same as that reported by Dunn 4 for White Leghorn pullets, ex¬ 
cept that his medium-weight group (52.00 to 59.99 grams) contained 
the largest percentage of fertile eggs that hatched, although the differ¬ 
ence in hatchability between his low (eggs weighing up to 51.99 grams) 
and medium-weight groups was not significant. The difference in 
percentage of hatchability between the low- and medium-weight 
groups in this study on Barred Plymouth Rocks is 2.16 ±2.45; be¬ 
tween the medium- and high-weight groups it is 13.15 ± 9.55; between 
the low- and high-weight groups it is 15.31 ±9.67. None of these 
differences in percentage of fertile eggs hatched are significant, 
whereas Dunn obtained significant differences between his medium- 
and high-weight groups and between his low- and high-weight groups. 
Briefly, then, in Dunn's White Leghorn pullets the larger eggs appear 
to have been somewhat less hatchable than those of small and medium 
size, while in the case of eggs laid by the Barred Plymouth Rocks 
used in this study the larger eggs also gave a lower hatching percent¬ 
age, but no significance is attached to it. 
Up to the present, the matter of a possible relationship between 
egg weight and hatching quality has been considered from the stand¬ 
point of the eggs from the flock as a whole. Since the results of 
several lines of investigation have shown, however, that variation 
in hatching quality of eggs has been found to be chiefly a variation 
among* individual fowls, it becomes necessary to consider the data 
shown in Tables V and VI on the basis of the mean weight of each 
pullet's eggs whose embryos died in shell and those which hatched, 
in relation to the percentage of fertile eggs which hatched. In other 
words, is there any correlation between the mean weight of the eggs 
of individual pullets and the percentage of their fertile eggs which 
hatched? To show something on this point, the mean weight of the 
eggs whose embryos died in shell and the mean weight of those 
which hatched for each pullet are given in Table VII. 
* Dunn, L. C. the relationship between the weight and the hatching quality of eggs. 
Conn. Storrs Agr. Exp; Sta. Bui. 109: 92-114. 1922. 
