THE SILK-COTTON TREE. 277 



running in streams from the main brandies, 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 fioivers 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 finally becomes sere before the au- 

 tumn. It is, perhaps, as early as July in these years, 

 when 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 ofiice 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 



