Ig2 BOTANICAL GAZETTE [MARCH 
dropped from it. A subordinate amount is formed from the remains 
of the aquatic vegetation preceding the sedges in the invasion of 
the basins and from the shrub-sphagnum vegetation which follows 
them. 
b) Illustrative localities 
To illustrate the course of the bog succession upon Isle Royale 
several representative localities will be briefly described. Amygda- 
loid Lake shows the bog plants gaining their first foothold along 
the shore; the two ponds near Tobin’s Harbor have been partially 
Fic. 32.—Amygdaloid Lake: in the eon a thick growth of Menyanthes and 
Listuele thyrsiflora; farther out, Nymphaea adve 
covered and filled; and the basin on Raspberry Island contains a 
completely covered bog. 
Amygdaloid Island lies parallel to 
the northwest shore of isle Roy ale and is formed by two partially 
submerged ridges of the usual kind. Between the ridges is an 
inclosed basin which contains a narrow lake, 100m. wide at the 
most, but 1.2km.long. It should be noted that Amygdaloid Lake 
is identically like the basin on Raspberry Island, to be described 
later, in situation and physiographic development. For some 
reason its history has not progressed so far, although both are at 
