178 THE LIFE OF A BIRD. 



ciple as an aid to the classification of birds is found 

 to be valuable on the whole ; and it is gratifying 

 to find that, were we to take the eggs of British 

 birds as our only guide, with the exception of a 

 few instances, we should arrive at the best and 

 most approved arrangement of the different ge- 

 nera. When it is remembered, that, after all, the 

 egg of a bird is in reality one stage or condition 

 in the life of the being, surprise need not be felt 

 that the eggs of different kinds of birds differ 

 from each other, or that those of one kind or genus 

 have a family resemblance to one another. The 

 greater marvel is, that they do not differ more 

 among the different genera than we find to be the 

 case. The eggs of insects differ much more re- 

 markably in their various genera than do those of 

 birds, and some of them are among the most 

 charming and beautiful objects in creation, when 

 beheld with the assistance of a lens. 



