152 THE BIRDS OF SHERWOOD FOREST. 



that in the alleged instances the young of the goatsucker 

 has been mistaken for that of the cuckoo a mistake 

 which might easily be made, from the similarity of the 

 plumage of the young of both species. 



The mode in which the cuckoo introduces her egg 

 into the nest of another bird has been made a greater 

 difficulty of than necessary, from the fact that usually it 

 would be a physical impossibility for the cuckoo to enter 

 the nest and lay her egg in the ordinary manner. I 

 have often found the egg, but never, (except in one 

 instance, where the shallow nest of the pied wagtail was 

 chosen), was the nest in such a position as to be reached 

 by the cuckoo otherwise than with her bill. The latter 

 is doubtless the instrument by which the egg is deposited 

 in its chosen place. 



But of all the extraordinary theories which have been 

 brought forward respecting the cuckoo, that advanced 

 by Dr. Baldamus of Stuttgart is the most amazing. It 

 was first published by him in 1853 in the Naumannia, 

 the leading ornithological periodical of Germany, but 

 had remained unknown to English naturalists until the 

 Rev. A. C. Smith called attention to it in the Zoologist 

 for March, 1868, and gave a translation of Dr. Baldamus's 

 paper in that periodical for the following month. I 

 would advise all my readers who are interested in the 

 subject to peruse that article for themselves, but for 

 those who have no opportunity of doing so I will give a 

 brief outline of the theory. Dr. Baldamus begins by 

 asserting that the eggs of the cuckoo are subject to great 

 variation, both in colour and markings, and that he had 

 found thirty-seven varieties ! He then set himself to 

 discover the cause of this singular variability, and after 

 some time spent in diligent research and examination, 



