Fig. 50. Water-striders have long, thin legs.
The insects which skip lightly over the surface of the water where the current is not too strong, are water-striders. ([Fig. 50].) Some are short and stout, others slender-bodied; but all have long thin legs. Their color is nearly black. As they scurry about in the sunshine the delighted watcher will sometimes catch a glimpse of their reflections on the bottom. Six oval bits of shadow, outlined by rims of light; there is nothing else like it! Be sure you see it.
Fig. 51. The dobson makes no pretensions to beauty. (Natural size).
Let us leave the quiet, restful pools and the sluggish bays, and follow the hurrying water to the rapids. Every stone changes the course of the current and the babble makes glad the heart of the wayfarer. Let us "leave no stone unturned," until we have routed from his favorite haunt that genius of the rapids, the dobson. ([Fig. 51].) These creatures bear other common names. They are prized by fishermen in the black bass season. Dirty brown in color and frankly ugly in appearance and disposition, these larvæ, for such they are, have little to fear from the casual visitor at the water's edge. When a stone is lifted, the dobsons beneath it allow themselves to be hurried along for some distance by the current. The danger over, they "catch hold" and await their prey farther down stream. In spite of their vicious looking jaws these insects are not venomous. At the very worst they could do no more than pinch the finger of the unwary explorer.
When the dobson is full grown, it is called a hellgrammite fly or horned corydalis. It has lost none of its ugliness, though it has gained two pairs of thin, brownish-gray wings, and flies about in the evening. It has been known to create some consternation by flying in at an open window. It is harmless and short-lived in the adult stage.
Upturned stones are likely to bring to view other strangers. Lying close against these wet stony surfaces one usually finds young May-flies. ([Fig. 52].[15]) These, like the young dragon-flies, are called nymphs.
Fig. 52. May-fly nymph. (Three times natural size)