164 THE LIFE OF A BIRD. 



variation being a result of accident, and not other- 

 wise to be found. The probability also remains, 

 that in most instances where a larger number 

 than usual has been artificially brought about, 

 a new set of eggs is produced, and produced by a 

 stimulus, which in ordinary cases could not have 

 taken place. It is well remarked, nature in- 

 variably pursues one course. Therefore, to draw 

 a general rule of her actions, we must strictly 

 adhere to her in an unmolested, uncultivated 

 state ; for if we deviate from that, we must infal- 

 libly err. 



The inquiry with respect to the size of eggs 

 remains in precisely the same unsatisfactory state 

 as we found that of their number, ornithologists 

 having paid very little attention to the collection 

 of any general facts upon this department of their 

 science. As it is, the proportion between the size 

 of birds and that of their eggs, is only recognised 

 by a sort of floating knowledge, the rules of nature 

 remaining still in a great measure unknown. It 

 may be taken as a general rule, that the egg of a 

 bird bears a proportion to its size. The egg of a 

 wren and that of an eagle have each their propor- 

 tion to the size of the parent. Yet, to the most 



