156 THE BIRDS OF SHERWOOD FOREST. 



deposition, when the act is a very rapid one. How then 

 could a sight of the eggs in a nest alter the colour of her 

 egg already matured ? 



Dr. Baldamus finally gives up this conclusion in 

 favour of the second, which I think is as unsupported as 

 the first Of course he admits that all the thirty- 

 seven kinds of cuckoos are specifically identical as 

 Cuculus canorus, and yet in one important point, 

 the colour of the eggs they lay, he alleges they are 

 specifically distinct. I cannot, I confess, understand 

 such an anomaly. The thirty-seven kinds are identical 

 in structure, plumage, and size, and yet each lays a 

 differently marked egg. But are we to suppose that 

 these thirty-seven kinds, visit a country at the same time, 

 feed on the same food, mingle in the same hedgerows, 

 and yet do not breed together ? The idea is incredible, 

 and yet the crossing which must of necessity take place 

 between these imaginary kinds, would of course destroy 

 in time the alleged distinctive markings of the eggs their 

 progeny would produce, and bring all to one uniform 

 character. 



I have dwelt at length on this subject, which is one 

 of great interest, but I must say that I should like 

 clearer proof than I at present possess, before I can 

 accept either conclusion. All who possess the oppor- 

 tunity should lend their aid in its investigation, and 

 accumulate such evidence as will either disprove the 

 theory, or make us willing to give up our long-cherished 

 opinions. 



The first point evidently is, do the eggs of the cuckoo 

 vary to the extent asserted ? I believe they do not j 

 and to this our observations should be directed, and 

 nothing but positive evidence admitted. 



