The Ohio Naturalist, 
PUBLISHED BY 
The Biological Club of the Ohio State University. 
Volume II, JANUARY. 1902. No. 3. 
TABLE OF CONTENTS. 
Schaffnf.r — Self-Pruning of Woody Plants 171 
Osborn — Mallopbagan Records and Descriptions 175 
Kellerman — M inor Plant Notes, No. 4 179 
Dury — W arblers Nesting Near Cincinnati . . 182 
Morse — Variations in the Water-Snake 183 
Morse— Myriopods from Vinton, Ohio 187 
Kellerman— Botanical Correspondence and Notes for Amateurs, II ... 188 
Hike — Notes on Ncuroptoid Insects 100 
Tyler - Meeting of the Biological Club 192 
THE SELF-PRUNING OF WOODY PLANTS. 
John H. Schaffner. 
In a former article* by Air. Frederick J. Tyler and the writer, 
the subject of the self-pruning of woody plants was discussed 
in a general way, and a number of notes were presented, giving 
the facts observed up to the time of publication. During the 
past year the writer has made further observations, which have 
confirmed the views previously expressed and also added some 
phenomena not mentioned in the former paper. The work was 
carried on during the summer in northern Kansas, and continued 
during the fall in central Ohio. 
The past summer was notable for the severe and long-continued 
drouth, which extended over a large portion of the interior. This 
cause may have had some effect on the cottonwood, Populus 
deltoides Marsh., which was self-pruning very abundantly before 
the 15th of July. Many of the branches cut off still retained 
perfectly green leaves, while on some the leaves were withered or 
yellow, and others were entirely defoliated before they fell to the 
ground. The tree shown in the picture (Fig. 1) was standing 
alone on the prairie. It was photographed on July 17, 1901, and 
at this time had already cast a large number of branches. 
It was discovered that from the middle of July up to the time 
of complete defoliation numerous branches with fresh, green 
♦Schaffner, John H., and Tyler, Fred. J. Notes on the Self-Pruning of Trees. Ohio 
Nat., 1 129-32, tool. 
