The Zoologist— May, 1873. 3507 



Natural History Society, and the paper he then read, having been 

 since printed in the ' Wiltshire Magazine' (vol.ix. p. 57), and else- 

 where, has, with Mr. Rowley's article, made the theory very 

 generally known. Mr. Smith also published, subsequently, in the 

 ' Zoologist' for 18G8, a translation of Dr. Baldamus's elaborate essay; 

 but this translation being unaccompanied by the coloured plate 

 which illustrated the original, unfortunately fails to do justice to the 

 Doctor's theory, for without seeing the specimens on which this is 

 founded, or good figures of them, the evidence in its favour can 

 scarcely be appreciated fully. 



Dr. Baldamus's theory had been some time known to me, when 

 in 1861 I had the pleasure of being shown by him his collection 

 of cuckow's eggs, and I can declare that his published figures re- 

 present the specimens (sixteen in number) from whichthey are drawn, 

 as faithfully as figures of eggs usually do, and that an inspection of 

 the series convinced me that the belief he entertained was not 

 groundless. All the eggs in question, some departing very widely 

 from what I had been used to regard as the normal colouring, bore 

 an unmistakable resemblance to those of the birds in the nests of 

 which they were asserted (in most cases, I was assured, on very 

 good authority) to have been found ; while in some cases there was 

 just enough difference between them and those they "mimicked," 

 to show that it was far more unlikely that they should have been 

 extraordinary varieties of the eggs of the species in question, than 

 eggs of the cuckow. 



Dr. Baldamus's allegation therefore seemed to me to be in part 

 proved. If the history of the eggs before me could be trusted — 

 and I had no reason to doubt it — the fact of the likeness was in many 

 respects self-evident, in others certainly not so striking, and in some 

 perhaps questionable. In further corroboration of the theory also, 

 there were the similar instances cited with much assiduity from 

 foreign sources by Dr. Baldamus in his essay,* and one, apparently 

 not known to him, but given by Mr. BIylh in Sir William Jardine's 

 ' Contributions to Ornithology" for 1850 (p. 69 his, pi. 52). Another 

 and very remarkable case had also come to my own knowledge. In 

 the autumn of 1857 I had received from Mr. Tristram all the eggs 

 collected by him in Algeria during the preceding season. When 



* I do not here enumerate them; they will be found in 'Naumannia' for 1851, 

 p. 317, note. The plate which illustrates the paper is in the volume of the same 

 magazine for the following year. 



