VIII 



THE ALDER FRINGE 



Who has not heard some gentle and harmless 

 poet singing of a brook fringed with alders? Not 

 such a bad thing in its way either, especially when 

 in autumn the bending limbs are twined with red- 

 berried bittersweet. The entomologist has a tale 

 to tell of another kind of alder fringe. He tells 

 it in the sober prose his profession demands. In 

 the first instance the alder is itself the fringe 

 along the brook's border. In the latter case the 

 fringe is of another sort. The alder stems are 

 hung with strands of filmy white silk. 



In early summer, when the brook has become 

 a mere thread trickling along under the heavy 

 green of its border plants, the stems of alder 

 begin to whiten. One need not wonder long, 

 for a single look discovers the cause. The canes 

 are covered with "woolly aphids," so called from 

 the white downy threads which exude from and 

 cover their bodies. At first sight one turns away 

 in disgust from the pulpy gray creatures which 

 looked so white and silky at a little distance. But 

 wait — let the entomologist continue his tale and 

 disclose to you the really marvelous inter-relation 

 between this downy insect and its neighbors. 

 But for its presence on the alder stems there 

 would be less sweetness set free in the world and 



(40) 



