548 THE ZOOLOGIST. 



usually does."* Mr. Wallace considers that these eggs "are 

 coloured in a specially protective manner," but it is equally open 

 to argument, that as white eggs are concealed, and the mottled- 

 grey egg of the Nightjar laid on the similarly coloured ground, so 

 the concealing, or active mimicking, powers of the Coot suggest 

 its placing its eggs among the leaves that so successfully hides 

 them. 



That birds may use a reasoning or cunning attribute in the 

 deposition of their eggs where the colouration may prove of an 

 assimilative character to the surrounding environment may be 

 argued from the evidence which exists of their pursuing an 

 equivalent mental process in the placing of their nests. Thus 

 recently a writer has described " some curious experiences in 

 birds' nesting." He found a Blackbird's nest " situated in a de- 

 pression in the ground, in just such a position as a Sky Lark's 

 might occupy." A keeper who accompanied him had found 

 several other Blackbirds' nests in similar positions. Within a 

 few hundred yards two Thrushes' nests were also found on the 

 ground, " the edge of the nests being level with the surface." On 

 enquiry it was stated " that the proprietor, having found that 

 this wood was a nesting stronghold of these species, had made 

 systematic raids on their nests in consequence of the havoc made 

 by the birds on his fruit. I think this fact suggests why these 

 birds had departed from their usual habit in their choice of 

 nesting sites. Profiting from experience, they had selected safer 

 positions." The same writer records facts to prove that the 

 Common Sandpiper " profits by experience, and occasionally 

 varies its choice of nesting sites." In 1886 these birds had their 

 nests twice swept away from the river-banks by heavy floods. In 

 the following year nests were found fully a hundred yards from 

 the river. " From May, 1886 (the date of these floods), until 

 1889, the Sandpipers continued to nest at some distance from the 

 river."! The Sumoan Tooth-billed Pigeon (Didanculus strigi- 

 rostris), which formerly bred on or near the ground, and was so 

 greatly reduced in numbers by Cats as to be threatened with 

 extermination, eventually took to nesting and roosting in trees, 

 and has since been gradually on the increase." | We have not 



* ' Darwinism,' p. 215. 



t Dr. K. Williams, ' The Zoologist,' 3rd ser. vol. xx. pp. 372-3. 



I F. A. Lucas, ' Rept. Nation. Mus.' Washington, 1891, p. 612. 



