(c). The Shrub Stage. With higher food demands this 

 stage follows only when, as in our lowland natural meadows, 

 these conditions are fulfilled. In several places this stage has 

 quite replaced the meadow, extending up to the very base of the 

 cliff. The first form to appear in the meadow is Diervilla trifida 

 which later becomes the character shrub of this stage. Spiraea 

 salicifolia latifolia follows, often becoming very abundant. Asso- 

 ciated but secondary forms are: Rubus strigosus, R. cana- 

 densis, Lonicera ccerulea, and Ribes prostratum. Alnus viridis 

 soon makes its appearance and becomes the dominant bush. 

 With it are Cornus stolonifera, Nemopanthes fascicularis, Ame- 

 lanchier oligocarpa, Primus virginiana, P. pennsylvanica and 

 Pyrus americana. With these shrubs is associated a mesophytic 

 undergrowth. Phegopteris Dryopteris, Asplenium filix-foemina, 

 and Aspidium spinulosum dilatatum all occur in greatest profu- 

 sion. Associated forms are Streptopus roseus, $. ample xifolius, 

 Clintonia borealis, Trientalis americana, Coptis trifolia, Galium 

 triftorum, Viola blanda, and V. canina. These forms precede 

 the mesophytic forest which encroaches below. This latter 

 society has been discussed above and need only be mentioned 

 here. One fact seems very evident ; whatever the pioneer stage, 

 the ultimate is the climax forest of this region. 



c. THE; POND-BOG SOCIETIES. 



The scene of general and local glaciations, the environs 

 of the mountains are dotted with ponds whose origin is 

 unquestionably morainic. A marked variation in size and 

 depth presents a variety of conditions which closely control 

 the plant life of these upland ponds. The low mean tem- 

 perature of the water and the destructive spring freshets 

 preclude an abundant acquatic vegetation in those ponds, Cowles, 

 Davis, and Chimney, which are situated at the base of the slopes 

 and receive the brunt of these spring devastations. In the ponds 

 this zone is the mesophytic climax forest. Sometimes an inter- 

 removed from these destructive agents, a slight aquatic vegeta- 

 tion sustains itself. 



(a) . The Pond Societies. The shores of these ponds are rock 

 strewn and slope off to some depth. A narrow zone of alder 



