54 Trans. Acad. Sci. of St. Louis. 



leaf injury. Osage orange showed the least effect of any 

 of the broad leaved trees. 



Conifers as a class were much less affected than were 

 the broad leaved trees. Scotch pine suffered most, but 

 even in the worst cases lost only a few leaves and showed 

 few wounds on the bark. Austrian pine was still less 

 affected than Scotch pine and red cedar showed no in- 

 jury. 



The relative resistance of the broad leaved species in 

 this storm is shown in the following table in which the 

 worst affected species are placed at the head of the table. 



DEFOLIATION. INJURY TO TWIGS, 



Catalpa (Catalpa). Catalpa. 



Sycamore (Platanus). Russian Mulberry. 



Russian Mulberry (Morus). Box Elder. 



Cottonwood (Populus). Cottonwood. 



Box Elder (Negundo) . White Willow. 



Black Walnut (Juglans). Sandbar Willow. 



Green Ash (Fraxinus). Sycamore. 



Silver Maple (Acer). Green Ash. 



Honey Locust (Gleditschia) . Silver Maple. 



White Willow (Salix). Black Walnut. 



Sandbar Willow (Salix). Honey Locust. 



American Elm (Ulmus). American Elm. 



English Elm (Ulmus). English Elm. 



Osage Orange (Madura) . Osage Orange. 



All species suffered most severely from defoliation on 

 the sides from which the storm came, while the worst 

 injury to twigs and branches occurred in the tops of the 

 trees and usually on such exposed branches as were most 

 nearly at right angles to the hail. This occasionally 

 caused the opposite side of the tree from which the storm 

 came to have more wound injury to bark than the side 

 from which the storm came. In four Carolina poplars 

 which were examined it seemed that less bark injury 

 occurred than in common cottonwood, and it is thought 

 that the sharper angle of branching had much to do with 

 this. Unfortunately time did not permit a search for a 

 sufficient number of these trees to determine this point. 



Trees with flexible branches suffered less than those 

 with stiff branches. Species with small twigs or with 

 hard wood suffered less than those with large twigs and 



