38 ROYAL SOCIETY OF CANADA 
cinium macrocarpon, the two latter forming the dominant vegetation; 
while the more elevated margins bear an abundance of Cyperaceæ suc- 
ceeded by ferns and grasses. In the present condition of this bog we 
find direct correspondence with the first peaty zone of the marsh 
directly overlying the cassandra zone. The absence of small pine in 
the case of the bog, and their presence in the corresponding zone of 
the marsh requires explanation, which is no doubt to be found in the 
very limited dimensions of the bog itself, since other, larger bogs in the 
same stage of growth, do show pine trees. 
The fourth bog studied is several acres in extent, and it affords a 
more complete epitome of the underlying structure of the marsh. In 
this case the sphagnum stage has been passed as in the preceding, and 
the bog has advanced well toward the completion of the cassandra 
stage. Cassandra calyculata forms a dense growth over very nearly 
the entire surface. Mingled with it are various other ericaceous plants 
such as Kalmia angustifolia, which appears only where the surface 
becomes locally somewhat more elevated and somewhat better drained. 
Numerous Cyperaceæ, especially cotton grass (Eriophorum) appear over 
the entire area, and in the lanes between the cassandra growth, there 
is such an abundant growth of the common cranberry (Vaccinium 
macrocarpon) that the berries are regularly sought and picked each 
year. 
The most significant feature of this bog for our present purpose, 
is to be found in the young growth of white pine which occupies all the 
more elevated areas. These trees are only a few inches in diameter 
and rarely more than six feet in height, although on a few of the most 
elevated areas there were found three trees upwards of fifteen feet in 
height. SAS. 
From these details it is evident that this bog is at present in that 
stage of development which embraces two of the zones of the marsh. 
The greater portion of the area is in the cassandra stage and, therefore, 
corresponds with the cassandra zone of the marsh. The more elevated 
portions which are in consequence better drained, bear a different type 
of vegetation including white pine, and this zone is the exact equivalent 
of the peat zone containing small stumps of white pine, as found in the 
marsh. If nothing arises to disturb the natural course of development, 
the present growth will be followed by another which will give rise to 
a peat zone derived from the remains of leaves and grasses, and it will 
then come to represent the equivalent of the upper peat layer of the 
marsh, or the layer immediately below the marsh turf. If further, at 
such time it were possible for the bog to be flooded by salt water and 
