NATURE'S GRAND CARAVAN 



water, flying at their natural time, pace, and height. 

 The long, exhausting, and dangerous journeys may 

 well be done in a very different way, such as Gatke 

 suggested at a great height and pace, and in the 

 dark. Storms threatening below, the birds might 

 mount with ease to a more serene height, and keep 

 at this plane, unless storms enveloped them, when 

 they swiftly might drop earth- or water-wards. 



When we watch the consummate ease with which 

 birds ride the air in their song, food, and court- 

 ship flights, the difficulty, in especial stress and 

 need, of lowering or raising themselves swiftly to a 

 different aerial plane does not strike us as formid- 

 able. The flying effort is perhaps the least difficult 

 thing about bird travel to understand. But how do 

 the travellers find their pathless way ? and what is 

 the impulse which gathers them together that vast 

 motley crowd, strangers often in species and habit of 

 life, the incomparable caravan of Nature ? 



The Anarch Rook 



The rook and the house sparrow have in common 

 a profound suspicion of man, and a strong taste for 

 his neighbourhoods. The sparrow, with all his 

 familiarity towards men, cannot be tamed as red- 

 breast or thrush. The sparrow's vigilance towards 

 men is, however, not more than the rook's. The 

 rook in his aerial pleasantries, his softened language 



73 



