465 
During the spring this area is very wet, forming a miniature 
pond, a few inches in depth, but in the summer and fall it is dry and 
sun-baked. 
STATION XVI. 
(Plate XV.) 
An oval depression on the highest portion of the intermediate 
ridge, about one hundred feet in longest diameter. The center of 
the pond is filled with cattails, about which is a zone of grass and 
aquatic plants. The pond is edged with bushes and bush-like trees, 
while the forest proper succeeds this formation. There are thus 
four different kinds of plant societies, or three zones surrounding a 
: 
Top, oe 
Ne tober eos 
eo 
earths eros C 2 O 
+, +% 
2% 00 
FIGURE 4. 
Diagram showing relation of characteristic vegetation of Station 
XVI. 
Cephalanthus occidentalis. 
Typha latifolia. 
Iris versicolor. 
Dulichium spathaceum. 
Sagittaria latifolia. 
Quercus coccinea. 5 
Quercus bicolor. 
Salix longifolia. 
Populus tremuloides, Corylus, Hamamelis, Viburnum, ete. 
tHKnNOP+0O @ * 
central nucleus. (Fig. 4.) The plant societies may be tabulated 
as follows, 
