250 FERNOW 



the mainland about twenty miles below Muir Glacier is 

 formed by the moraines of the receding glacier, old 

 enough to be diversified into a maze of hills and valleys, 

 the top varying from dry, coarse gravel to pure sand and 

 finer silt towards the point. The interior portions, mostly 

 in the nature of sand dunes cut through by low, swampy 

 places and occasional clear rivulets, are more or less 

 without vegetation, at least without forest growth, except 

 on the compacter gravels, where Pinus contorta has 

 established itself in open growth. 



Along the shores, however, is a belt of varying width, 

 consisting of a dense growth of spruce with an occasional 

 and poorly developed hemlock ( Tsuga heterophylla) or 

 balsam poplar, while the shrubby alder and willows occupy 

 ravines and draws, and line the skirts of the spruce forest. 

 The soil under the spruces is densely covered with a 

 heavy carpet of mosses among which three or four species 

 are prominent, with the pretty Listera, the constant com- 

 panion of the shady spruce, and a Pyrola which grows 

 in the darkest corners, while a Vaccinium and the brake 

 (^Pteris aquilina) occupy the more open places. Be- 

 sides these, species of Ribes, Viburnum, Satnbucus, 

 Streptopus, Lycopodium, Aruncus, and the prickly 

 Echinopanax are present. 



This spruce forest, as can be readily ascertained by 

 counting the internodes and the annual rings of a few cut 

 trees, is all between forty and fifty years old. The largest 

 trees are as much as thirty-six inches in diameter and 

 eighty feet in height, showing the remarkable rapidity of 

 growth which characterizes the tideland spruce. 



The history of the evolution of this forest and of the 

 recovery of the ground by vegetation is written in clear 

 language. First the rough gravel of the moraine was 

 colonized by the prostrate willows and the Equisetum 

 and Epilobium that grow on the moraine in front of 



