Life-history of the Cuckoo. 129 



invests every hen Cuckoo with the faculty of laying eggs, coloured 

 like the eggs of the bird, of whose nest she prefers to make use, 

 according to the locality ; or in other words ; ever}' hen Cuckoo 

 lays eggs only of a fixed colour, corresponding with the eggs of 

 that warbler, in whose nest she lays them (as a general rule): and 

 she only lays in other nests, when at the time for her laying, one 

 of the species, of her own peculiar type, as we may say, which is 

 fitted for her in every particular, is not ready."] 



Such is the very interesting and well sustained argument of Dr. 

 Baldamus : and however new and startling his hypothesis, however 

 unprecedented his conclusions, yet he supports his argument with 

 such a battery of facts that his position seems almost impregnable. 

 Facts are proverbially stubborn things, and not to be overthrown 

 by opinions held only from the force of habit and not from conviction 

 of their truth. At the same time I am far from advocating any 

 acceptance of conclusions, until we have tried them and ascertained 

 their value. And so I would urge upon every outdoor observer, 

 (and everybody who lives in the country ought to be an out-door 

 observer) to assist in investigating this curious question, and I 

 would invite them to communicate to this Natural History Society 

 any discoveries they may make, or any well ascertained facts they 

 may elicit. We have a new point before us in the history of the 

 Cuckoo suggested for our consideration : we all hear the Cuckoo's 

 cry every spring all around us : we know then that the bird is with 

 us, laying its eggs in our neighbourhood : it requires only diligence 

 and observation and patience to make us acquainted with its habits. 

 But yet again I would repeat the caution against rushing too 

 quickly to conclusions : it is not an isolated fact here or there that 

 would warrant any inference : it is only by careful comparison of 

 many well authenticated particulars, that we are able to arrive at 

 any satisfactory decision. While on the other hand, the question 

 before us is not to be set on one side as the dream of an enthusiast, 

 or the fancy of a superficial naturalist. It is deliberately proposed 

 by a leading ornithologist, of mature judgment and deep scientific 

 attainments : it is the result moreover of patient research, and a 

 long course of enquiry among men well calculated to form a right 



