EXPERIMEXT STATION BULLETINS 



183 



common name of witch's brooms, Hexenbesen, the Germans call them. These witch's 

 brooms continue to increase in size, and when a number of branches are diseased, 

 the tree finally dies as a result of the attack. This parasite is widely distributed in 

 the Upper Peninsula. I saw it in nearly every swamp from Chatham to Soo Junc- 

 tion, a distance of one hundred miles. In some of these swamps nearly every tree 

 had been killed. 



Diseased branches of the Black Spruce. 



The damage done by the mistletoe is considerable, but just how great cannot be 

 determined without farther examination. While examining the plants in the office, I 

 found that the mistletoe was also attacked by a fungus parasite, which must have a 

 tendency to check the spread of this pest. Each fruit is attacked at its apex by the 

 fungus WallrotJiiella arccuthobii. Peck, and. of course, destroyed. This mistletoe 

 was first found by ISIrs. L. A. Millington, a former resident of Michigan, at Warrens- 

 burg, New York. It was discovered the same year by C. H. Peck, state botanist of 

 New York, who also found the fungus, and who gave both parasites their names. The 

 cuts on earlier pages give a good notion of healthy and diseased spruce trees. 



C. F. WHEELER, 

 Botanist of Experiment Station. 

 Agricultural College, Nov. 1, 1900. 



