358 PROCEEDINGS OF THE ACADEMY OF [June, 



assumed a tree-form descent commences in the five-year-old 

 branches, and they finally curve and recurve as in the Spruces. 



Koelreateria. 



This seems naturally tortuous ; but the branches, once formed, 

 seem unchangeable. 



^sculus. 



A. Hippocastanum recurves remarkably, even in Ijranches of 

 considerable age. 

 Acer. 



The Maple family : A. dasycarpum, the Silver Maple, is remark- 

 able for its eccentricity as regards the curving of its branches. 

 One form known in gardens as " Wier's Cut-leaved," has cord- 

 like pendulous branches, some of which straighten eventually and 

 ascend. The leading branches are mostly erect, and aid in the 

 heightening of the tree. Some individuals of the ordinary trees 

 recurve branches in great numbers when these are several years 

 old ; other specimens show no recurving of individual branches. 

 The recurving of weaker branches is a common feature. A. 

 saccharinum, the common Sugar Maple, seldom recurves the larger 

 branches; but the weaker ones fi'equently begin to curve when two 

 or three years old, and continue to such an extent as often to 

 form almost a circle. The species can be recognized at long dis- 

 tances by this character. In A. rubrvm, the Red Maple, I see no 

 disposition to curve; in A. platanoides none; but it occurs to a 

 small extent in A. Pseudo-Platanus. A. macrophyUum, the Oregon 

 Maple, has the branches at a rather acute angle, with an incurved 

 apex. This character seems unchangeable, and my thirty-year- 

 old tree has a broomy character. A. camptestre, A. latum show 

 no curving characters. 

 Negundo. 



In the Ash-leaved Maple I observed no tendency to curve in 

 either the Atlantic or Pacific coast species. 



Sophora. 



Neither in this nor in Rohlnia, Gleditschia nor any leguminose 

 plant have I noted any disposition to curve mature branches. 



Pyrus. 



In the rosaceous family the Pear is characteristic in recurving its 

 mature branches as it advances in life. In mv earlier vears the 



