are self-pruned in the spring or early su 



s the poplar, postpone the process until fall. 



C. Stuart Gac 



THE TARDY DEFOLIATION OF THE TREES. 



The significance of leaf-fall as a protection against excessive 

 drought rather than against extreme cold, as is popularly sup- 

 posed, is well shown in the late persistence of the foliage this fall. 

 Normally, most of the deciduous trees and shrubs in the Garden 

 are almost entirely barren of leaves by the last of October, but 

 this year the foliage, though richly colored with autumn tints, has 

 persisted until the last week in October, with almost no sign 

 of falling. Some of the maples, the hornbeams, sweetgums, and 

 even the plane-trees (which have already been once defoliated 

 this season by a fungus disease attacking them in the spring), 

 show, at a distance, almost no loss of foliage. 



This fact is doubtless largely due to the copious precipitation 

 during September. Seven and ninety-three hundreths inches of 

 rain were recorded at the Garden last month, or almost one fifth 

 of the entire average annual precipitation. Thus tardy leaf-fall 



several frosts that have occurred have not appreciably hastened 

 defoliation. Of course loss of water by transpiration ceases some 



NEW MUSEUM CASES. 

 The crowding of specimens resulting from the naturally uneven 

 growth of the different parts of the museum during the last few 

 years has necessitated an increase in the case equipment for both 

 the public exhibits and the study collections. To meet this con- 

 dition, a number of cases were recently constructed and set up 

 under a contract of the Department of Parks. These represent 

 several standard units, and are built of quartered oak to match 

 the cases of their respective styles. 



