84 Further Facts and some Results. 



flying from a pied wagtail's nest, two or three feet 

 below her face, on a pear tree on the wall, and that 

 the bird had what looked like an egg in its bill, and 

 two small brown birds were flying at it. Her atten- 

 tion was first called to it by hearing a great noise and 

 fluttering. I at once climbed to the wagtail's nest 

 and found one fresh cuckoo's egg and one wagtail's. 

 I am quite certain that cuckoos usually abstract one 

 or two (perhaps rarely more) of the foster-parents' 

 eggs in exchange for their own." 



A few years ago Colonel Butler found a green- 

 finch's nest in his garden in the north of Suffolk, with 

 one egg in it, which he marked with a pencil. A day 

 or two afterwards the nest contained a cuckoo's egg, 

 and the marked greenfinch's egg was picked up on a 

 path a considerable distance from the nest ; almost 

 certainly dropped there by the cuckoo. 



Mr. J. H. Gurney also gives evidence sufficient to 

 prove that sometimes, at least, the old birds do remove 

 the true nestlings from the nest. This may be in 

 certain cases where the young cuckoo for various 

 reasons may have been unable to throw them out. 



The late J. J. Briggs mentioned a circumstance 

 which would indirectly tend to establish this, if we 

 admit that, when the adult cuckoo throws the true 

 nestlings out of the nest, it would also naturally, at 

 the same time, try to guard its young from enemies. 



The circumstance was this. \\'hen passing a cer- 

 tain point he saw a cuckoo strike down at his dog, 

 and try to dodge or entice it away from a certain 

 place. He found a young cuckoo was close by there 

 in the nest of a hedge-sparrow. Dr. J. B. Gray tells 

 us that he had seen a cuckoo, day after day, visiting 



