LIFE ZONES 457 



have continuous though not intense light in 

 summer, and a long winter night ; but alpine 

 summits are lighted by day and dark by night, 

 as are the lowlands. Alpine heights are dis- 

 tinguished by the extreme beauty and great 

 abundance of the flowers, which are large in 

 proportion to the often mosslike plants which 

 bear them. The fauna includes such animals 

 as the mountain sheep and the ptarmigan, 

 the latter a grouselike bird which turns white 

 in the winter, the color of the snow which 

 everywhere surrounds it. 



(b) Hudsonian Zone. So called because it is well 



developed in the vicinity of Hudson Bay. 

 It is a zone of dense coniferous forests, with 

 here and there a flowery meadow. In the 

 west it is of importance as the recipient and 

 conservator of the moisture which ultimately 

 finds its way into the streams and irrigates 

 the varied crops of the plains. The soil, 

 largely composed of vegetable debris, and 

 sheltered from the rays of the sun, acts as a 

 sponge and provides for a continual stream 

 flow instead of roaring but transitory torrents. 



(c) Canadian Zone. A zone of mixed vegetation, 



with aspens, various conifers, and small fruits 

 such as blackberries, raspberries, and cran- 

 berries. This is the first zone in which we 

 find crops, unless timber is regarded as a crop. 

 The potato, timothy grass, and some of the 

 more hardy cereals are regularly grown. The 

 glades and meadows are filled with tall and 

 luxuriant herbaceous plants, of the type of 

 vegetation known as mesophytic, that is, 



