126 Darwin mid Roinajies dealt with. 



do. It is easy to be seen that, as no brooding comes 

 in to interrupt the laying, she must at the least lay a 

 dozen eggs, and that is allowing a good deal more 

 than four days between each of them. If the de- 

 mands of migration would, in our country, make it 

 impossible that she should rear and feed, after fledg- 

 ing, the young from an egg still in the nest on 25th 

 of June, this certainly cannot apply to the eggs laid 

 up to the second week of May and before it. 



A point for Dr. Charles Creighton : if our cuckoos 

 go on laying eggs up to anything like the date given 

 here for Gibraltar (and I have proof that they do it 

 in record of my own observations), then that would 

 allow nearly, if not quite, a fortnight for observation 

 after the date he sets down with such decision for 

 Jenner, and, from my own experience, a good deal 

 can be observed in a fortnight by one who can devote 

 all, or almost all, his time to a special purpose, and 

 has some scientific curiosity, determination, and 

 patience to lie or to stand still for hours. 



All Mr. John Hancock's observations of young 

 cuckoo turning out eggs and young of hedge-sparrow 

 were within a fortnight — nay, really within a week ; 

 while Mr. John Craig's yet more remarkable and 

 fruitful observations and experiments, resulting in a 

 whole series of valuable and unique snapshots, de- 

 scribed in the preface, were really accomplished in 

 eight days in the case of one nest, and in the case of 

 the other, within a week. 



And this position of mine is certainly confirmed by 

 Mr. J. H. Gurney's words : 



" The latest egg I have found was on June 28th, 

 but Colonel Butler tells me of a fresh egg in a yellow- 



