CAUSE OF VARIETY IN. 155 



this bird lays two, and sometimes three eggs. 

 These form grave exceptions to this generally re- 

 ceived rule as to the number of eggs and the size 

 of the parent. 



Not to multiply instances of the same kind, we 

 may content ourselves with observing that the 

 extreme limits of the kingdom of birds, in point 

 of size, present us with the most remarkable excep- 

 tion to the above rule that can be conceived. The 

 ostrich, the greatest of birds, lays about seven 

 eggs ; while the insect-like humming-bird deposits 

 only two delicate eggs in its tiny nest. 



It results from these considerations that the rule 

 has so many exceptions as to be almost valueless 

 in point of accuracy ; and some other principle 

 must be laid down, if we would define the laws 

 which regulate the number of eggs in the various 

 families of birds. In all probability the number of 

 the eggs of birds, which is in effect the same as 

 the abundance or scarcity of the members of an in- 

 dividual family, has been wisely regulated by the 

 Author of Creation, with a view to the accomplish- 

 ment of certain great objects in the scheme of 

 being. We shall be more in the right track if we 

 seek for the explanation, or, at least, for a partial 



