NOTES. 577 



exit ". It may be of interest to compare its nest with that of the South 

 American Oven-birds (Furnarius, &c.). 



Note 53, p. 221. Doves beside falcons. 



Those interested in the facts of nature which suggest the danger of 

 exaggerating the Darwinian idea of the struggle for existence should con- 

 sult two articles by Kropotkine, entitled " Mutual Aid Among Animals ", 

 in the Nineteenth Century, 1889. Kropotkine cites from Dr. Coues, an 

 American ornithologist, an observation in regard to some little cliff swallows 

 which nested quite near the home of a prairie falcon. " The little peaceful 

 birds had no fear of their rapacious neighbour ; they did not let it even 

 approach to their colony. They immediately surrounded it and chased it, 

 so that it had to make off at once." 



Note 54, p. 223. And they know that this is so. 



Brehm suggests here and elsewhere what it would be difficult to prove, 

 that animals which have unconsciously acquired protective colouring, and 

 which instinctively crouch or lie still instead of trying to escape by flight, 

 are aware of their adaptation to concealment. There seem to be but few 

 cases which give countenance to this supposition. 



Note 55, p. 227 '.Crocodile Bird. 



This is usually regarded as Pluvianus or fly as cegyptius one of the 

 " plovers " in the wide sense. Professor Newton observes, however, in a 

 note to the article " Plover" in his Dictionary of Birds that there is not per- 

 fect unanimity on the matter, as some have supposed that the " crocodile 

 bird " was a lapwing Hoplopterus spinosus. But the elder Geoffroy St. 

 Hilaire and Brehm, who both saw the bird enter the reptile's mouth, 

 regarded it as Pluvianus cegyptius. 



Dr. Leith Adams notes (1870) that the crocodile is now rarely seen 

 below Beni Hassan, and is evidently receding everywhere below the second 

 cataract. Both Herodotus and Strabo speak of its domestication, and it is 

 tamed at the present day by certain religious sects in India. On the 

 lower Nile it is shy and difficult even to shoot. 



"A sail, or the smoke and noise of a steamboat, suffice to warn the 

 crocodiles basking on the sand-banks, or their common companions, the 

 black-headed and spur- winged plovers (Pluvianus cegyptius and Hoplopterus 

 spinosus), which are frequently seen perched on their backs, and always 

 prepared to give timely warning of approaching danger, just as the Father 

 of History noticed them 2300 years ago, and, strange to say, his well-known 

 story is current among the modern Egyptians, who, as bsual, have put a 

 tail to the narrative. They say, that in addition to its office of leech- 

 catcher to the crocodile, it occasionally does happen that the zic-zac so 

 called from its note of alarm in searching for the leeches, finds its way 

 into the reptile's mouth when the latter is basking on a sand- bank, where 

 it lies generally with the jaws wide apart. Now this is possible and 

 (M70) 37 



