324 ALBINISM. 



the distance of a yard or two, and forming a comfortable 

 warm lodging for the night. * 



It might appear at first sight that such a manoeuvre 

 must be attended with great risk of injury to the birds ; 

 as for instance, if they should happen to strike against 

 a branch, or other hard object buried beneath the 

 snow ; but the great depth of the drifts, and the exceed- 

 ingly fine, dry, powdery nature of the snow, seems 

 to render it as safe for them to dive into, as the water 

 is for a gannet, fishing in the sea. We know that 

 the gannet will suddenly plunge into the water with 

 great force from a very considerable height, but expe- 

 rience shows that whether it be into water or into 

 snow, in neither case do the birds seem to ruffle as 

 much as a feather, while executing these bold feats 

 with that perfect confidence which is born of a know- 

 ledge that they may perform them with impunity 

 and in performing them, the birds, no doubt, instinct- 

 ively close their wings and feathers, so that they 

 plunge into the opposing element, which then merely 

 serves to press or smooth the feathers closer to the 

 body, without doing the slightest injury to them. 



The question of the white, or protective colours of 

 arctic birds and animals, of which the ptarmigan is 

 a conspicuous example, is a matter which deserves a 

 brief notice. There are some glass cases in the South 

 Kensington Museum, containing groups of these birds, 

 and small animals, which illustrate very beautifully this 

 phenomenon of protective colouring, both in the desert 

 and in the arctic zones. The instances of this pro- 



* Out of Doors in Tsarland, a Record of Wanderings in Russia, by 

 Fredk. J. Wishaw, 1893, PP- IJ 5 IT 7- 



