TYPICAL SWAMP AREAS. 57 
fruits floating everywhere, and shortly after the water has 
subsided, the ground is thickly covered with little seedlings 
whose continuance depends on their ability to keep their 
heads above water when it rises. In the latter part of 
October, they were observed to be about a foot in height 
and growing vigorously and rapidly. The soil at that time 
was comparatively dry. Every gradation in size may be 
observed in the tupelos of these river swamps. In one 
region they were mere shrubs, not exceeding twenty feet 
in height. In certain other areas where the Nyssa is en- 
tirely dominant, young trees from thirty to fifty feet in 
height are standing straight and close together, the crown 
of leaves high up and very few branches below. (Plate 1.) 
Near the water line occurs the characteristic bulge in the 
trunk which becomes so pronounced in the older tree. For 
a considerable space above and below this water line, the 
trunks in April were covered with a species of Porella 
which seems to thrive luxuriantly in this habitat. As the 
tupelos in the swamp grow older, one finds the lower por- 
tion of the trunk continuing to increase in diameter and 
soon forming a dome-shaped base quite different in appear- 
ance from the cone-shaped cypress base in a similar habi- 
tat. (Plate 18.) This process is accompanied by the 
dying away of the tops and the decay of all central tissue 
until the tree consists of a hollow dome with the shaft 
above usually broken off thirty or forty feet above the 
ground, a few scattering limbs bearing what scanty foliage 
remains. 
The tissue of the tree is often torn partially from the 
roots as the base enlarges, and infoldings occur at the rup- 
tured points which become covered with bark. Similar 
crevices or splits above the roots often appear as the trunk 
increases in size, and the bark soon covers the edges and 
extends some distance within the inner surface. At the 
time the photograph of the large tupelo shown in the upper 
figure of Plate 19 was made, there was 22 inches of 
