i82 Darw'ni and RoiJiaiies dealt with. 



the feeding of the aliens prevents a second brood. 

 The instinct in these httle birds unquestionably proves 

 to be of exclusive use and benefit for another species 

 — the cuckoos. 



Mr. John Hancock tells that, in the course of his 

 watching the young cuckoo turn out eggs and young 

 of the foster-parents, the hen hedge-sparrow actually 

 sat on the edge of the nest and uncoiiceniedly saw one of 

 its own young sent over the side — a thing so counter 

 to the common instinct that we can only assume a yet 

 stronger instinct there brought into play — an instinct 

 of which we can give no explanation — only clearly it 

 is there. Air. John Craig remarks precisely to the 

 same effect. We should indeed be glad if Dr. Russel 

 Wallace could give such an explanation as we desire 

 here. 



Mr. Tom Speedy tells {Craigniillar, p. 197) of a 

 young cuckoo which was found by a gentleman, and 

 taken home to form a pet. It was so voracious that 

 he would have needed to give his whole time to hunt 

 for insects, etc., for it. It was never satisfied. To 

 get rid of it, he gave it to Mr. Dewar, naturalist, 

 Edinburgh, who kept it on make-shift diet for a fort- 

 night, when an enthusiastic lady naturalist, Mrs. 

 Hoyes, of Skelmorlie, asked for it. She put the 

 cuckoo into a large aviary, as she tells, where " a- 

 mong many other birds, were American blue robins." 

 She was surprised, when feeding it with meal worms, 

 and accidentally dropping one, to see a little blue 

 robin pick it up, and at once pop it into the cuckoo's 

 mouth. She subsequently observed that the same 

 bird fed it regularly, and showed fight to any other 

 bird that dared to come near it. •' Instances have 



