174 Rhodora [SEPTEMBER 
there is a characteristic bog of somewhat more than an acre in extent, 
known as Wheeler’s Bog. The central portion is at present occupied 
by a perfectly clear water field, while the margin, which is extending 
rapidly toward the centre, and occupies about two-thirds the entire 
area, affords an exceedingly fine example of the Cassandra stage in 
bog development. Here and there, however, small islands have gained 
a slight elevation above the Cassandra growth and exhibit the com- 
mencement of the next stage, that of broad-leaved trees, in which the 
common birch is represented. All about the margin of the bog, and 
extending into the interior of the Cassandra growth, there is an abun- 
dance of Rhodora which attains to a height considerably above 6 
dms. Owing to the inaccessible character of the bog, it was not pos- 
sible to take actual measurements, but there was a very strong im- 
pression that some of the bushes must be at least 9, and possibly 
12 dm. in height. The particular point I wish to emphasize is the 
fact that this location affords a striking illustration of the typical 
habitat of Rhodora, which is described in the manuals as inhabiting 
“Cool bogs.” ! 
A few days later, on the occasion of a visit to St. Andrews, New 
Brunswick, an opportunity was afforded for the examination of 
certain localities there. St. Andrews is somewhat farther north than 
Shelburne and is in close proximity to salt water, but judging by the 
character of vegetation, there is reason to believe that there can be no 
great climatic difference between the two places and for our present 
purposes, they may be regarded as essentially the same. 
Geologically speaking, Shelburne is to be regarded as representing a 
much older geological formation than St. Andrews. The surface 
deposits consist of drift material derived in the main from Laurentian 
gneisses, intrusive granites and other rocks extending into the early 
Palaeozoic as far as the Cambrian. То this must also be added the 
material derived from erosion of innumerable trap dykes which inter- 
sect the older rocks everywhere. 
At St. Andrews, on the contrary, the surface structure has been 
derived chiefly from red sandstone, usually regarded as Devonian, 
with which there has been mixed to some extent, the detritus of granite 
and trap dykes. How far this difference in the character of the soil 
may be a factor, it is at present impossible to say, as no observations 
in that direction have been made. 
1 The latest revision of Gray's Manual specifies '' swamps and moist slopes." 
