MIMICRY. 545 



I have related my own experience in the Transvaal with 

 Francolinus levaillantii, a single member of which from a covey I 

 had disturbed squatted in a small hole in the path about eighty 

 yards in front of me, and, depressing its back level with the earth, 

 exhibited a good instance of the protection obtained by assimila- 

 tive colouration.* A young Merganser deceived the Duke of 

 Argyll and a party of his visitors at Inverary by simply remaining 

 perfectly still on ground on which it was inconspicuous by reason 

 of the protective resemblance or mimicry of its colour.! Mr. R. 

 Kearton states : — " I have on more than one occasion seen a baby 

 Peewit wandering about with half of its prison-house still attached 

 to its downy rump, and if a Hawk or other bird of prey should 

 happen to appear overhead they instinctively clap flat upon the 

 ground, and remain motionless as stones until the danger has 

 passed."! The Dabchick, on quitting the nest, according to Mr. 

 Hudson, " invariably draws a coverlet of wet weeds over the eggs ; 

 the nest in appearance is then nothing but a bunch of dead 

 vegetable rubbish floating in the water. "§ Young Emus are very 

 different in colour from the old birds, and bear a delicate design 

 of a pretty dark grey with numerous stripes on their back and 

 sides. Mr. Semon relates : — " Young Emus are often pursued 

 by Eagles and Hawks so frequent in Australia. When (so my 

 blacks told me) the young Emus see a bird of prey soaring above 

 them they quickly lie down flat upon the ground. A body as big 

 as theirs would surely be much more conspicuous, set off as it is 

 by grass, if it were evenly though ever so modesty coloured, than 

 if its colouring be varied by stripes and spots. I myself have 

 had occasion to notice how difficult it is to discover an Emu in 

 the grass if it nestles to the ground." || Gilbert White remarks 

 on the Stone Curlew (CEdicnemus crepitans) : — " The young run 



:;: ' A Naturalist in the Transvaal,' p. 75. — Subsequently I observed how 

 this action could become habitual without a suitable environment. I flushed 

 a pair of Francolinus subtorquatus, one of which squatted in the same 

 manner, but, by force of circumstances, among the short, black, and charred 

 remains of a grass fire. Here its colour stood out in bold relief, and I easily 

 bagged it. 



j- Cf. W. Lauder-Lindsay, ' Mind in the Lower Animals,' vol. i. p. 526. 



I ' With Nature and a Camera,' p. 210. 



§ ' Birds in London,' pp. 99-100. 



|| ' In the Australian Bush,' pp. 145-6. 



Zool. Mh ser. vol. III., December, 189U. 2 N 



