THE LIFE -SPOT. 207 



comes thicker and thicker, until it becomes almost 

 like a layer of dense white parchment. 



The last and most important part of the struc- 

 ture of an egg remains for our examination. The 

 yolk is a thin yellow fluid, suspended in the white, 

 and prevented from mingling with it by a mem- 

 brane which is called very appropriately the 

 yolk-bag. It is described as being deposited in 

 very delicate membranous cells, having a honey- 

 comb arrangement. In shape, as every one knows, 

 the yolk is globular, almost spherical. Its posi- 

 tion in the egg can be pleasingly shown by cutting 

 a hard-boiled egg in half; the parts being all solid, 

 this is easily effected by means of a very sharp 

 and thin knife. 



On the surface of the egg, and uppermost in 

 every position in which it can be placed, is a little 

 spot which, from its roundness, can always be seen 

 to be clearly distinct from the rest of the egg 

 which is called the cicatricula^nd is in fact the germ 

 of life in the egg. It is the point from which the 

 future bird is developed, and is slightly elevated 

 above the rest of the yolk. Into the minuter 

 structure of the yolk it is not here necessary for us 

 to enter. But it is highly interesting to inquire 



