THE SILK-COTTON TREE. 
277 
running in streams from the main branches, and 
forming those projecting spurs that obliterate the 
angles from the main roots ; and the result is a 
ligneous deposition, of greatest density where the 
streams strike off from the trunk. With this un- 
equal deposit of wood, is accomplished those flattened 
buttresses which become so remarkable a feature in 
this gigantic tree. 
‘‘ The Eriodendron is one of our few deciduous 
trees. By deciduous trees I mean trees exhibiting 
that suspension of vegetative energy for a determi- 
nate period of time, which not alone is an exhibition 
of hybernation, but of a state in which the leaves are 
entirely shed, and the tree stands bare and verdure- 
less, — an economy very unusual in tropical trees. 
Now this hybernation is annual ; but the succession 
of leaves, though annual too, is biennial as foliage 
only, or as flowers and seed-pods, and eventually 
as leaves. 
In every third year, the foliage comes out early 
after the latter rains, and continues thickening and 
darkening, and Anally becomes sere before the au- 
tumn. It is, perhaps, as early as July in these years, 
w’hen no further sap flows from the roots to the leaf- 
buds, that it ‘ declines into the sere and yellow leaf.’ 
The leaves having by that tim.e ceased to perform 
their office of vegetative lungs, and to give out 
oxygen to the atmosphere under the action of the 
sun’s rays, the sap is descending as pulp to the roots. 
The twigs are beginning to harden and shrink, and 
if not emptied, are now so drained by the terminal 
buds, which are elaborating flowers for the year to 
