April, 1908.] 
The Vegetation of Cedar Point. 
3°3 
The Ulmns-Acer Forest Formation. 
Facies: Ulmus americana, 
Acer rubrum. 
Secondary Species: 
Fraxinus americana , 
Quercus velutina, 
Platanus occidentals, 
Sambucus canadensis, 
Rubus nigrobaccus, 
Parietaria pennsylvanica, 
Lactuca florid ana, 
Helianthus decapetalus, 
Solanum nigrum, 
Boehmeria cylindrica 
Campanula americana, 
Dryopteris spinulosa, 
Fraxinus lanceolata. 
Acer nigrum, 
Ostrya virginiana, 
Rubus occidentals, 
Ribes cynosbati, 
Parthenocissus quinquefolia, 
Impatiens biflora, 
Phytolacca decandra. 
Galium triforum, 
Botrychium virginianum, 
Circaea lutetiana, 
Enpatorium ageratoides. 
The accumulation of humus in the soil of the ridge as well as 
the general rise of water in the Lake has brought about a gradual 
change towards mesophytic, or even hydrophytic, conditions so 
that this formation, as represented on Ridge No. 1, is practically 
the same as would be the formation derived upon the filling up of 
a hydrophytic pond or swamp by the accumulation of humus. 
In either case there is a rich humous soil with great capillarity 
and a high water table. 
The formation as represented on Cedar Point is not of large 
area and it has, moreover, been much disturbed by man’s acti¬ 
vities, and no effort was made on the part of the writer to deter¬ 
mine the minor formational structure. 
THE LAGOOX-MARSH-WET MEADOW-THICKET-FOREST SUCCESSION'. 
In the writer’s studies on the ecology of Presque Isle there 
was found to be represented there a remarkable series of lagoons, 
these being evident in all stages from extreme youth to mature 
old age, so that the successive development of the lagoon vege¬ 
tation was not difficult to decipher. On Cedar Point, however, 
the lagoons are few and the successional series is rather incomplete. 
Nevertheless, such stages as are in evidence show much similarity 
to corresponding stages on Presque Isle so that, by correlation, 
a fair idea may be gained of the probable structure of the lagoon 
vegetation for the missing stages. 
For a lagoon or pond the normal tendency is to become filled 
with accumulating vegetable debris, the surrounding vegetation 
being arranged in concentric zones, each inner one more hydro¬ 
phytic, and, with the accumulation of vegetable debris and the 
elevation of the respective habitats, there is a continual advance 
of all the zones towards the deeper central portion of the lagoon 
