THE CHATS. 355 



but is resident the whole year; and yet is is more 

 limited in its distribution than either of the other two. 

 Now these three species all resemble each other in 

 their habits, and rear about the same broods, and yet 

 the one which is apparently exposed to the fewest ca- 

 sualties, either natural or artificial, is the least abun- 

 dant. While the wheatear braves the sea, in the 

 storms of spring and autumn, and extends its adven- 

 turous flight as far as Greenland itself; and while in 

 many countries, and in England among the rest, it is 

 captured in great abundance for the table, the numbers 

 seem never to diminish. The stonechat, on the other 

 hand, braves no sea, takes no long and exhausting 

 flight upon the land, is seldom in districts where it can 

 be much pushed for food, and yet its numbers do not 

 increase ; it does not appear to extend its range even 

 in proportion as cultivation ameliorates the northern 

 parts of the island. 



This increase against circumstances, and want of 

 increase where these are in favour, is probably more at 

 variance with the present state of our theories of the 

 numbers of animals, than any other instance that 

 could be named. In one case of disparity of increase, 

 we have a difference in the numbers of the young. 

 The brood of the eagle is seldom more than two, and 

 often only one, while that of the partridge is as many 

 dozens. The whale, too, brings but one, while the 

 brood of the cod fish is a number of thousands. We 

 can, therefore, easily see why there should be more 

 cod fish than whales, and more partridges than eagles. 

 In the latter case, too, we can see how cultivation 

 should diminish the number of eagles, and increase 



