CUCKOO. INSESSORES. CUCULUS. 399 



its copartners. It has been suggested by MONTAGU, and I 

 should think, with great probability, that the Cuckoo may 

 possess the power of retaining its egg in the oviduct at plea- 

 sure, otherwise it would be difficult to account for some phe- 

 nomena connected with its history. 



The continuation of the species appears to require such a 

 provision to have been granted, for, as he observes, if the 

 Cuckoo was obliged, like other birds, to lay its eggs, five or 

 six in number, successively day after day, it is hardly pro- 

 bable it should find (within that time) sufficient nests in the 

 exact state to receive them ; much less, if it laid a greater 

 number of eggs, as has been suggested. The rare occurrence 

 of the Cuckoo's egg being found, gives additional strength to 

 this supposition, for although the old birds may be seen in 

 abundance, such a discovery has seldom been made. 



Naturalists have been puzzled to account for this bird 

 not performing the office of incubation, but as their re- 

 searches have principally been directed to the anatomical 

 structure, in which point it does not essentially differ from 

 many others that perform this office, we arrive by these 

 means at nothing satisfactory. The above peculiarity of this 

 remarkable genus must not probably be looked for in any 

 principle of conformation, but must be explained from their 

 habits and economy. 



Let it be remembered these birds are migratory, and that 

 the period during which the adults remain with us, is very 

 short ; but the propagation of the species must be effected 

 during that period. Now, as their arrival does not take 

 place before the month of April, and the egg is seldom ready 

 for incubation before the middle of May, there would not be 

 a sufficient length of time for the young to be hatched, or 

 (making every allowance,) sufficiently fledged to accompany 

 the old birds at the period of their departure, which seldom 

 or never extends beyond the first week in July. 



The egg requires a fortnight's incubation, and the young 



