42 THE BROOK BOOK 



and forgiven. We cannot blame her since it is 

 instinct that leads her to neglect our pet brooks. 

 A lusty young caterpillar, destined later to become 

 a Wanderer butterfly, hatches from each egg. A 

 score of these can produce great havoc in a 

 colony of w^oolly aphids. Nature provides that 

 not all shall be destroyed, and year after year the 

 fringing alders are themselves decorated w^ith this 

 living fringe. 



The alder-blight produces honey-dew, and thus 

 supplies nourishment for other forms of life. Ants, 

 bees and wasps take a share, and there is yet 

 another pensioner. Down on the ground a lowly 

 fungus had long been struggling with its neigh- 

 bors for mere existence. At last it reached a 

 point where the soil was wet with honey -dew 

 as yet unused by the other plants. The fungus 

 feasted, grew and throve, rearing its black spongy 

 bulk above the surface of the ground. The alder- 

 blight blessed it with clear showers of liquid sweet- 

 ness day by day. Wanderers of a human kind 

 may know this pensioner of the woolly aphis by 

 its black spongy mass, and if they like may learn 

 to call it Scorias spongiosum. If they wish to be 

 very entomological they may call the alder-blight 

 by its given name, Scbizoneura tessellata. What- 

 ever we call it, let us learn its history and take 

 note of its useful life, though in time it may 

 destroy a part of our pet alder fringe. 



