122 CUCULUS CANORUS. 



has it not abundance of food ? does it not go away at the very 

 time when insects and larvae are most abundant ? If it dreads 

 the cold of early autumn, is not that of April or even May 

 much greater ? and if its tender young find enough of heat un- 

 til September, how is it so much more sensitive ? It has been 

 alleged, conjecturally I believe, that the ovary is less plentifully 

 supplied with blood than that of other birds of similar size, and 

 therefore the eggs are not developed. I can see no difference 

 in this respect between the Cuckoo and the Magpie or Jay ; 

 but if there were, although the smallness of the eggs might be 

 accounted for in so far, how is it necessary that they should be 

 small 1 In short, all that we know about the matter is just 

 this : The Cuckoo arrives in the end of spring, and departs in 

 July ; it forms no nest, but deposits its eggs singly in the nests 

 of various small birds, which hatch them, and rear the young. 

 The latter not being well fledged until September, remain two 

 months behind their parents. 



The eggs of birds are not proportioned to their size. The 

 single egg of the Auks is enormously large ; the three eggs of 

 the Cormorant very small ; the numerous eggs of the Geese 

 moderate ; those of the Wren very large. It is as incompre- 

 hensible that a Guillemot should lay only one egg of extrava- 

 gant size, as that a Cuckoo should lay twenty of the opposite 

 kind. Were we to suppose that eggs few in number are pro- 

 portionally large, observation would convince us that this is 

 not always and regularly the case. The Curlew lays four eggs ; 

 and the Hooded Crow five ; but although these birds are nearly 

 equal in size, one of the eggs of the former weighs more than all 

 those of the latter. The Hock Pigeon and Jackdaw are about 

 the same size ; so are their eggs ; but the former lays only two, 

 and the latter five. It must not therefore be said that the 

 Cuckoo's eggs are very small, because they are very numerous. 



According to the statement of M. Temminck, the phenomena 

 in question have been explained as follows : — " M. Schlegel, 

 one of the assistant naturalists of the museum, has furnished, 

 in an essay crowned by the Natural History Society of Harlem, 

 details of the greatest interest as to the very probable causes which 

 induce the Grey Cuckoo, as well as all the species which lay 



