Mr. Seehohrns Reproductions. 51 



eggs of one colour. This can only be surmised by- 

 analogy, though the one fact bearing on the question 

 is where two cuckoo's eggs were found in the same 

 nest [and] which differed greatly. More might have 

 been learnt from the incident, had it been known for 

 certain whether the eggs were laid by the same or 

 different birds. There is a general tendency in the 

 habits of animals to become hereditary, and it seems 

 not unreasonable to suppose that a cuckoo which has 

 once laid its egg in the nest of any particular species 

 should continue to do so, and that the young cuckoo 

 should also continue the practice in after years." 



Mr. Seebohm's reproductions of cuckoo's eggs, 

 however, show that this writer was in the greatest 

 possible error in declaring the cuckoo's eggs to be in- 

 variably brown, which suggests the idea that, while 

 right on some points, he wrote from imperfect know- 

 ledge in others, and was not himself a close observer. 



Mr. Bidwell's list gives 120 species in the nests of 

 which the cuckoo drops its eggs, and in the Zoologist 

 for 1883 he writes that " five eggs are said to be laid 

 in the season by the cuckoo at intervals of seven or 

 eight days ; " but this is surely an exaggeration. It 

 is probable, however, that the cuckoo has more power 

 than other birds in retaining perfect eggs in the ovary 

 — a point supported by a fact thus given by Mr. J. 

 H. Gurney : 



"Our Norwich bird-stuffers have on two or three 

 occasions taken perfect eggs out of cuckoos, which 

 indicates some latent power of retaining them in the 

 ovarium — a power long ago suspected by Montagu." 



Mr. Romanes, in his Animal Intelligence, writes in 

 a note at the end of his chapter on " Bird Intelli- 

 gence : " 



