BIRDS FLYING INTO SNOW DRIFTS. 27 



earth, and that which lives thereon, from the effects 

 of intense cold. 



Nothing that is done by Nature, we may depend 

 upon it, is done except as part of one grand and 

 homogeneous design, no part of which is without its 

 uses. 



It is in this way for instance that the ptarmigan, or 

 snow grouse, whose habitat is known to extend beyond 

 the highest latitude yet reached by arctic explorers, 

 actually finds a refuge and a habitation within the 

 snow drift ; for if alarmed they will fly fearlessly right 

 into it, and are then and there buried out of sight, like 

 a rifle bullet, in an instant, but without, be it observed, 

 sustaining any injury, even to the feathers, owing to 

 the condition of the snow, of which we have here 

 spoken. Further details of we trust both an instructive 

 and an interesting nature will be found respecting 

 these, and kindred subjects, in our arctic section. 



The most noteworthy features of the climate, through- 

 out "the region of the great plains," are its extreme 

 variability and great range of thermometric temperature, 

 which according to the seasons are almost everywhere 

 met with. 



The traveller cannot proceed far beyond the limits 

 of the desert zone without becoming aware that he 

 has passed out of the region of cloudless skies and 

 constant brilliant sunshine. In this damper climate, 

 except during the summer season, or where it actually 

 adjoins the rainless region, more or less cloud is gene- 

 rally present in the sky, and rains are liable to occur 

 suddenly at any time of year. The alternations of 

 heat and cold, too, become rapidly more and more 

 clearly marked as the traveller moves away from the 



