STRUCTURE OF AN EGG. 



181 



outline of the most important parts in the structure 

 of the egg. It is 

 however necessary 

 that, in order to 

 give a clear and 

 distinct idea of our 

 subject, we should 

 describe with a lit- 

 tle more minute- 

 ness their various 



parts. The annexed cut will in so doing greatly 

 assist the memory, by impressing a clear view of 

 the general contents of the egg, with the names of 

 its various portions. 



Outermost of all is the hard encasing structure 

 or shell, (fig. 1.) At the broadest end of the egg 

 is an empty, or rather air-filled space, called the 

 air-follicle, (fig. 2.) Within the shell is disposed 

 the shell-membrane, which divides into two layers 

 at fig. 4, and by the interval thus left the air-fol- 

 licle is formed. Surrounding the yolk, and between 

 it and the walls of the shell, is a thicker middle 

 part of the white, the boundary of which is marked 

 by fig. 5. Next to the yolk is a still thicker part 

 of the white, contained within the line, (fig. 6.) 



