BROOKLYN BOTANIC GARDEN 
LEAFLETS 
The Brooklyn Institute of Arts and Sciences 
Series 1 Brooklyn, N. Y., Octorer 29, 1913 Number 14 
LEAF-FALL 
The Fall of the Year. Spring is the season of preparation for 
life more abundant. Streams that yesterday were held in the icy 
grasp of winter begin once more to rush in swollen volume, waves 
again begin to dance and roll on the surfaces of ponds aud lakes; 
migratory birds return to breed and sing; insects burst from dry 
cocoons and sail away; buds are bursting, seeds are germinating, 
flowers are blooming, leaves expanding. 
Autumn, on the other hand, is a season of preparation for 
winter. Life in our climate is becoming quiescent; Migratory 
birds are leaving; insects are spinning cocoons; buds are matur- 
ing; flowers are giving place to fruit; seeds are ripening: leaves 
are falling. 
The Fall of the Leaf. The shedding of leaves is one of the 
most striking and at the same time one of the most wonderful 
of all plant adjustments to external conditions. In the first place 
it is wonderful because it anticipates. The external condi- 
tion that makes it neccessary has not yet been realized; winter 
has not arrived; and yet the tree makes ample preparation. In 
the second place, leaf-fail is wonderful because it is a distinct life- 
process. The leaves are not separated from the tree in a passive 
way, as dead branches are blown off by the wind; they are active- 
ly shed, and in some cases actually pushed off. This is accom- 
plished as follows. 
How it is Accomplished. Toward the end of the growing 
season, a thin layer of cells, frequently of cork, forms at the 
