The Zoologist— Apeil, 1873. 3473 



I cannot see any reason why the eggs of the cuckoo should 

 resemble those of the foster-parents, as the generality of small 

 birds will sit just as readily upon substituted eggs as upon their 

 own. 



There is nothing improbable in a hen cuckoo laying only eggs 

 of a similar colour, as this frequently occurs with other birds. 

 I knew an instance of a hen blackbird's laying all her eggs of a 

 spotless blue ; the first nest was taken, and a second nest was soon 

 built near the same spot, and the eggs were exactly like those in 

 the first nest: the female was probably a bird of the preceding 

 year. 



If the cuckoo has not a previous knowledge of what the colour 

 of her eggs will be, how can she decide in the nests of which bird 

 she is to place her eggs ? Perhaps Dr. Baldaraus supposes that 

 she lays one first, and after examining it decides upon the bird 

 which is to be the foster-parent of her young one. 



Henry Doubled^y. 



Epping, March 13, 1873. 



The Cuckoo Qnestion.-^k fact that most naturally opposes itself 

 in the minds o[ British ornithologists to the belief that the eggs of 

 cuckoos resemble in colour those of the birds in whose nests they 

 are introduced, is that, so far as I am aware, no one has ever found 

 in the nest of a hedgesparrow a cuckoo's egg which is similar to 

 that of the hedgesparrow. I should be extremely obliged if any 

 one or more of your correspondents would, in the course of the 

 coming breeding season, try whether the bird last named has any 

 objection to foster eggs of a colour entirely different to its own, 

 and communicate with me on the result of the experiment.— J//)e(; 

 Newton ; Magdalene College, Cambridge. — ' Field: 



Supplementary Jiemarks on the Propagation of the Cuckoo. 

 By the Rev. Alfred Charles Smith, M.A. 



As in this month's ' Zoologist' I have again taken up my parable 

 on the cuckoo (S. S. 34.3.3), in reference to the colouring of its eggs, 

 I am desirous to follow up the subject with some further observations 

 in regard to another interesting particular in the economy of thai 



