IN GREEN ALASKA 



observed and collected. The varied thrush or Ore- 

 gon robin was common, and its peculiar song or 

 plaint, a long, tapering whistle with a sort of burr 

 in it, led Ridgway a long chase through the woods 

 before he could identify the singer. Other song-birds 

 found were the western robin, the two kinglets, a 

 song sparrow, the Alaska hermit and russet-backed 

 thrushes, the lutescent warbler, the redstart, the 

 Oregon junco, and a western form of the savanna 

 sparrow. 



Gustavus Peninsula seems to be a recent deposit 

 of the glaciers, and our experts thought it not much 

 over a century old. The botanists here found a good 

 illustration of the successive steps Nature takes in 

 foresting or reforesting the land, — how she creeps 

 before she walks. The first shrub is a small creeping 

 willow that looks like a kind of "pusley." Then 

 comes a larger willow, less creeping ; then two or 

 more other species that become quite large upright 

 bushes; then follow the alders, and with them vari- 

 ous herbaceous plants and grasses, till finally the 

 spruce comes in and takes possession of the land. 

 Our collectors found the first generation of trees, 

 none of them over forty years old. Far up the moun- 

 tain-side, at a height of about two thousand feet, they 

 came to the limit of the younger growth, and 

 found a well-defined line of much older trees, show- 

 ing that within probably a hundred years an ice 

 sheet two thousand or more feet thick, an older and 



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