THE HEN'S EGG. 117 



2. Note the thin membrane lining the shell. 



3. Does the egg completely fill the shell? Where is the 

 air-space ? Does the lining membrane, in this region, 

 adhere to the shell or to the " white " ? How can a 

 fresh egg be distinguished, without breaking? Does 

 a fresh egg, in water, lie in the same position as when 

 on a table ? What is the use of this air-space ? 



4. How is the yolk situated in the white ? how in refer- 

 ence to the position during boiling ? Compare a num- 

 ber of eggs, to see if there is any regularity about this. 



5. Note the round spot on the yolk, where it comes near- 

 est to the surface. This is the germ -spot, in which 

 the chick begins to form. 



6. With a sharp knife, split the egg lengthwise. Is the 

 white alike throughout ? is the yolk alike throughout ? 

 has the yolk a coat ? Cut and tear these parts to make 

 out their structure, if they have any definite structure. 



7. Boil an egg hard, as before ; mark a line lengthwise 

 around the egg, passing through the point that was 

 uppermost while boiling; carefully break away the 

 shell on one side, and with a clean cut remove this 

 half of the white and yolk ; place the other half in 

 the position it had while cooking ; make a drawing of 

 this section, using different colors to show the shell, 

 shell-membrane, air-space, white, yolk, germ-spot, etc. 



8. Prop an egg on end, and boil in this position ; is the 

 yolk in a different position in consequence? The 

 white of the egg has interlacing fibres and partitions 

 which keep the mass together ; the white cannot be 

 mixed with water till these membranes are cut or 

 broken; hence an egg, to be eaten raw, should be 

 whipped to break these membranes. The white is not 



