414 



George E. Nichols, 



The discussion of these is deferred until later (see under head 

 of raised bogs, p. 433). 



3. The Formation-types of Uplands along Streams 



THE ASSOCIATION-COMPLEXES OF RAVINES AND VALLEYS 



The association-types of ravines. — Streams in the forested 

 region for the most part flow through ravines or broadly 

 V-shaped valleys. The character of the stream-bank and cliff 



Figure 59. — Low forest in ravine, with barren hill-top above ; barrens 

 in mountains west of Ingonish. 



vegetation here is essentially similar to that already described for 

 lowland streams. Ravine forests exemplify further the general 

 tendency of the vegetation of uplands in this region toward uni- 

 formity, since they differ scarcely, if at all, from the forests of 

 ordinary uplands. 



Ravine vegetation in the barrens (Fig. 59), in general, 

 resembles that of the forested region, and the forest-clad slopes 

 here may afiford a striking contrast to the barren aspect which 

 prevails on adjoining exposed uplands. In shallow ravines the 

 woodland is low, but in the deeper "gulches" the trees attain 

 considerable size. 



