142 THE LIFE OF A BIRD. 



mean number of females ; and this product multi- 

 plied by 5, the mean number of eggs laid by those 

 birds to whose care the cuckoos usually entrust 

 their offspring, gives 3,479,325, the mean annual 

 number of nestling birds destroyed by young 

 cuckoos in England and Wales. Enormous as this 

 destruction appears, it is probably rather under 

 than over-rated. If the cuckoo had selected the 

 nest of birds with a less numerous offspring than 

 those small birds, it would have materially assisted 

 to exterminate the species thus selected. Nothing 

 is wasted in the operations of nature ; and though 

 at first thought it might appear that this is an 

 exceptional instance, yet when we remember the 

 large amount of food thus provided for various 

 minute carnivorous animals who regale themselves 

 upon the bodies of the young which have met this 

 untimely end, the appearance of waste is removed. 

 And if the lover of rural scenes and sounds were 

 asked whether he would consider the loss of the 

 cuckoo's falling third melody compensated for by 

 the spared lives of the hedge-sparrow, and others, 

 it may be questioned whether he would not choose 

 the former of these alternatives, and assent to the 

 sacrifice, that the music might not be lost to the 



