The Cuckoo. 293 



either of them from the nest. When it is about twelve 

 days old, this cavity is quite filled up, the back assumes 

 the shape of that of nestling birds in general, and at that 

 time the disposition of turning out its companion entirely 

 ceases. The smallness of the Cuckoo's egg, which in 

 general is less than that of the hedge-sparrow, is another 

 circumstance to be attended to in this surprising transac- 

 tion, and seems to account for the parent Cuckoo's 

 depositing it in the nest of such small birds only as these. 

 If she were to do this in the nest of a bird that produced 

 a larger egg, and consequently a larger nestling, the 

 design would probably be frustrated, the young Cuckoo 

 would be unequal to the task of becoming sole possessor 

 of the nest, and might fall a sacrifice to the superior 

 strength of its partners. Dr. Jenner observes, that the 

 egg of two Cuckoos are sometimes deposited in the same 

 nest ; and gives the following instance which fell under 

 his observation. Two Cuckoos and a hedge-sparrow 

 were hatched in the same nest ; one hedge-sparrow's egg 

 remained unhatched. In a few hours a contest began 

 between the Cuckoos for possession of the nest; and 

 this continued undetermined till the afternoon of the 

 following day, when the one which was somewhat 

 superior in size, turned out the other, together with the 

 young hedge-sparrow and the unhatched egg. The con- 

 test, he adds, was very remarkable; the combatants 

 alternately appeared to have the advantage, as each 

 carried the other several times nearly to the top of the 

 nest, and again sank down oppressed by the weight of 

 its burden; till at length, after various efforts, the 

 strongest of the two prevailed, and was afterwards 

 brought up by the hedge-sparrow. 



The American Cuckoo, or Cow bird, is quite differ- 

 ent in its habits to the European Cuckoo, as it builds a 

 nest for its eggs, and hatches its young itself like other 

 birds. 



