182 THE LIFE OF A BIRD. 



At each side of the yolk are the vital portions, 

 (fig. 7,) called the chalazce. These are attached to 

 the yolk, (fig. 8.) In the centre of the latter is a 

 little space called the yolk-cavity, (fig. 9,) from 

 which a little canal or duct proceeds upwards, 

 (fig. 10,) to a little glanular mass, (fig. 11,) imme- 

 diately above which lies, (fig. ^^thegerm, the minute 

 point from whence the future bird is to be produced. 

 Let us now glance at the structure of each of 

 these parts in succession. First, as to the shell. 

 It cannot have escaped the notice of those who 

 have given even a small degree of attention to the 

 familiar objects by which they are for ever sur- 

 rounded, that the texture and appearance of eggs, 

 exclusive of their colour, is greatly different in 

 different instances. There is a difference percep- 

 tible to the attentive eye between the characters of 

 the respective eggs of the common fowl and of the 

 duck. Quite distinct from their respective colours, 

 and shapes, and sizes, there is a difference of what 

 we can call by no more appropriate title than 

 texture between these eggs, and this becomes still 

 more evident in the employment of a lens. The 

 eggs of a crow, again, differ in some degree from 

 both. These appearances have been considered 



