290 ANIMAL INTELLIGENCE. 



only the bill remaining above the surface for respiration. 

 When the swan has young, she may sink the head quite 

 under water in order to allow the young to mount on it, 

 and so be carried through even rapid currents. 

 The same author remarks that 



Many birds will carefully remove the meetings of the young 

 from the neighbourhood of their nests, in order not to attract 

 the attention of enemies ; for while we find that birds which 

 make no secret of their nesting-places are careless in such 

 matters, the woodpecker and the marsh tit in particular are at 

 pains to remove even the chips which are made in excavating 

 the cavities where the nests are placed, and which might lead an 

 observer to the sacred spot. 



Similarly, Jesse observes : 



The excrement of the young of many birds who build their 

 nests without any pretensions to concealment, such as the swallow, 

 crow, &c., may at all times be observed about or under the nest ; 

 while that of some of those birds whose nests are more indus- 

 triously concealed is conveyed away in the mouths of the parent 

 birds, who generally drop it at a distance of twenty or thirty 

 yards from the nest. Were it not for this precaution, the ex- 

 crement itself, from its accumulation, and commonly from its 

 very colour, would point out the place where the young were 

 concealed. When the young birds are ready to fly, or nearly so, 

 the old birds do not consider it any longer necessary to remove 

 the excrement. 



Sir H. Davy gives an account of a pair of eagles which 

 he saw on Ben Nevis teaching their young ones to fly ; and 

 every one must have observed the same thing among 

 commoner species of birds. The experiments of Spalding, 

 however, have shown that flying is an instinctive faculty ; 

 so that when he reared swallows from the nest and liberated 

 them only after they were fully fledged, they flew well im- 

 mediately on being liberated. Therefore, the ' teaching 

 to fly ' by parent birds must be regarded as mere en- 

 couragement to develop instinctive powers, which in virtue 

 of this encouragement are probably developed sooner than 

 would otherwise be the case. 



A few observations may here be offered on some 



