APPENDIX. 379 



well-closed hive : this ventilation has been artificially imi- 

 tated,* and as it is carried on even during winter, there can 

 be no doubt that it is to bring in free air and displace the 

 carbonic acid gas : therefore it is in trutli indisj^ensable, and 

 we may imagine the stages — a few bees first going to the 

 orifice to fan themselves — by which the instinct might have 

 been arrived at. We admire the instinctive caution of the 

 hen-pheasant Avhich leads her, as Waterton remarked, to fiy 

 from her nest and so leave no track to be scented out by 

 beasts of prey ; but this again may well be of liigli import- 

 ance to the species. It is more surprising that instinct 

 should lead small nesting birds to remove their broken eggs 

 and the early mutings, whereas with partridges, the young of 

 wliich immediately follow their parents, the broken eggs are 

 left round the nest ; but when we hear that the nests of 

 those birds (Halcyonidie) in which the mutings are not 

 enclosed by a film, and so can hardly be removed by the 

 parent, are thus "rendered very conspicuous ;"t and when 

 we remember how many nests are destroyed by cats, we 

 cannot any longer consider them instincts of trifling import- 

 ance. But some instincts one can hardly avoid looking at as 

 mere tricks, or sometimes as play : an Abyssinian pigeon 

 when fired at, plimges down so as to almost touch the sports- 

 man, and then mounts to an inmioderate height 4 the 

 Bizcacha (Lagostomus) almost invariably collects all sorts of 

 rubbish, bones, stones, dry dung, &c., near its burrow : 

 Guanacoes have the habit of returning (like Flies) to the 

 same spot to drop their excrement, and I saw^ one heap eight 

 feet in diameter ; as this habit is conmion to all the species 

 of the o-enus, it must be instinctive, but it is hard to believe 

 that it can be of any use to the animal, though it is to the 

 l*eruvians, w^ho use the dried dung for fuel.§ ]\Iany analogous 

 facts could probably be collected. 



Wonderful and admirable as most instincts are, yet they 

 cannot be considered as absolutely perfect : there is a con- 



* Kirby and Spence, Entomology, vol. ii, p. 193. 



t Blytli in Mag. of Nat. Hist., N.S., vol. ii. 



+ B race's Travels, vol. v, p. 187. 



§ See my Journal of Researches^ p. 167 for the Guanaco ; for tlie 

 Bizcaclia, p. 145. Many odd instincts are connected with the excrement of 

 animals, as with the wild Horse of S. America (see Azara's Travels, vol. i, 

 p. 373), A\-ith the common House Fly and with Dogs; see on the urinary 

 deposits of the Hyrax, Livingston's Missionary Travels, p. 22. 



