SIZE, SHAPE AND PHYSICAL CONSTITUTION OF THE EGG. 10/ 



the eggs of one of the others. Some of the birds laid eggi 

 which were long and narrow^ others those which were short and 

 broad. The eggs of some individuals were distinctly pointed, 

 while those of others were not. 



Not only was it possible to see this individuality by compai- 

 ing the eggs of the different individuals laid at the same sea- 

 son, but by preserving some of the shells of the eggs of each 

 bird at various seasons it was possible to see that the relative 

 size and the shape of the eggs of a fowl are to a large extent 

 permanent characteristics of the individual. 



The present investigation deals primarily with the quantita- 

 tive or measurable characters of the egg, but that the individ- 

 uality of the different birds manifests itself also in certain 

 qualitative characters is illustrated by a comparison of the coloi 

 and markings of the eggs of the different birds. 



This variation which is seen by a comparison of the eggs 

 themselves is shown equally clearly by a comparison of the 

 measurements of the characters. It is not confined to the ex- 

 ternally visible characters (dimensions, shape and size) but 

 extends to the size and the proportion of the parts which make 

 up the egg. 



A statistical analysis of the data shows the following points : 



INTER-INDIVIDUAIv VARIATION. 



1. The characteristic eggs of the different individuals show 

 variation in all egg characters. 



2. They differ more in size than in shape, and they differ 

 more in the amount of albumen and shell than in the size of the 

 yolk. 



3. There is a general correlation between the various char- 

 acters of the egg. That is, when a bird's eggs are large they 

 are both long and broad and contain a large yolk with a large 

 amount of albumen and shell. The amount of yolk, however, is 

 not proportionately large, so that the birds which lay large 

 eggs lay eggs which have a relatively small percentage of yolk. 



4. In spite oi this general relationship the eggs of one in- 

 dividual may vary disproportionately in any one of the char- 

 acters measured. 



5. There is an evident individuality among the birds also 

 in the amount of variation in the egg characters. The uniform 



