432 Proceedings Portland Society Natural History 



coniferous forest region, since the altitude is nowhere great 

 enough to effect the development of this particular climax. 

 There is also an absence of the characteristic vegetation of 

 ravines, flood plains and open valleys or intervales, since 

 these topographical forms are lacking. In other respects 

 the two regions are very similar, the chief difference being 

 the much larger percentage of spruce over balsam fir in the 

 coniferous forests. 



The Penobscot Bay region, as would be expected, shows 

 an even greater similarity to the island of Mount Desert 

 which lies on the eastern border of the Bay. An ecological 

 investigation of this island is under way at the present time 

 and some preliminary observations have already been pub- 

 lished (see Moore 19, 20). Five chief associations are rec- 

 ognized: the spruce, white pine, cedar, pitch pine and gray 

 birch-aspen together with several minor associations, one of 

 which is the spruce-northern hardwood. All of these types 

 are to be found in the adjacent Penobscot Bay region where 

 the first four constitute physiographic climaces ; and the 

 gray birch-aspen wood represents a stage of the secondary 

 succession after a fire or lumbering. The spruce-northern 

 hardwood forest is of more frequent occurrence than on 

 Mount Desert, but only in the localities well back from the 

 coast. 



Hawley and Hawes (14) in their map of the forest re- 

 gions of New England make Penobscot Bay the boundary 

 on the coast between the white pine region, which extends to 

 the western border, and the spruce region, which begins oil 

 the eastern border of the Bay. In the ojjinion of the writer 

 the white pine region should not be considered as distinct, 

 for it represents merely a physiographic climax on sandy 

 sterile soils in an otherwise deciduous area. But if it is so 

 recognized, the region should not be extended as far east 

 along the coast as Penobscot Bay. The forests on the west- 

 ern side of the Bay are of the same nature as those of the 

 eastern side, which are classed as "spruce" by Hawley and 



