356 SUMMER. 



that of partridges, as the one will not nestle except 

 in lonely places, or seek for its food near the haunts 

 of man ; while the other prefers the cornfield, and 

 nestles near the house. We can understand why a 

 change in the produce or appearance of a country 

 should occasion a change in the wild inhabitants ; why 

 drainage should send away snipes, bitterns, and all 

 manner of water birds ; and why plantations should 

 bring the warblers, the wood pigeons, and all the other 

 birds that love the covert. But in a genus of birds, 

 to whose apparent habits there has been no obvious 

 alteration ; where, if there has been a change for the 

 worse to the one, there has apparently been the same 

 change to the other, and where the change appears 

 to have been the better for them all : that, under such 

 circumstances, with an equal number of young an- 

 nually, and no dangers or casualties that are at all to 

 be compared, the stonechat should yet be a limited 

 bird, and the wheat ear so very general, is really an 

 anomaly, and shows that there must be some law that 

 regulates the numbers of animals with which we are 

 not yet acquainted. The difficulty is not solved, the 

 discovery is not made, though we say that, in the 

 absence of the birds of passage, the resident ones have 

 to sustain all the plunder of the birds of prey; for 

 there are birds of prey in those countries where the 

 travellers go in the winter ; and they have still the 

 fatigue and the casualties of the two journies against 

 them. This is therefore a fact, in natural history, for 

 which, in the mean time, there is no satisfactory ex- 

 planation, an indication of a law, of which there are 

 some traces in other parts of nature, as in the case of 



