136 MAINE AGRICULTURAL EXPERIMENT STATION. I 9 I 4 . 
ent degree of correlation. There is a general tendency for a 
given pair of characters to be similarly related in the eggs of 
the several individuals, but different individuals may show 
significantly different degrees of correlation in any pair of 
characters. 
2. Length and breadth are significantly but not highly cor- 
related. Both length and breadth are significantly correlated 
with the weight of the whole egg and of each of the egg parts. 
Breadth is as a rule more highly correlated with these weight 
characters than is length. The shape of the egg as measured 
by the length-breadth index is negatively correlated with the 
weight of the egg and with the weight of each of the egg parts. 
3. The weight of each part of the egg is positively corre- 
lated with the weight of both the other parts. 
III. Intra-individual Variation. 
1. The variation among the eggs of the same bird is shown 
to be related to certain other changes in the bird. 
2. The egg weight and the weight of the egg parts, es- 
pecially the weight of the yolk, increases as the bird matures. 
The rate of this gain in weight decreases with the successive 
months. 
3. Each part of the egg shows a seasonal fluctuation in 
weight which is apparently related to the general seasonal fluc- 
tuation in the physiological activities of the bird, expressed 
also in the curves for food consumption and egg production. 
4. The state of health also may affect the size of the egg. 
5. The size of the egg is related to the rate of production 
as it expresses itself in the laying of litters. As a rule the first 
and last eggs of a litter are smaller than the intermediate ones. 
6. When eggs are produced on successive days they tend 
to decrease in weight while the egg laid on a day after one on 
which no egg is produced is larger than the last egg of the pre- 
ceding series. 
