136 MAINE AGRICULTURAL EXPERIMENT STATION. I9I4. 



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 difTererit 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 Jength. The shape of the egg as measured 

 by the length-breadth index is negatively correlated with the 

 v/eight 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-indvuidual 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 afifect 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. 



