Read it through once

At the summit of the higher hills, bare rock crags projected out of occasional alpine grassy slopes, or irregular terraces, ravines, and gullies. Below, these alpine ravines ended in a peat-moss, which scattered, dwarfed, distorted, and miserable-looking Scotch Firs and Birches painfully endeavoured to colonize. Here and there on very steep hillsides, wiry, tussocky grass might be growing instead of forest or peat.