"But there are places in the world where the people do want to know these things, and a great many more, about the May-flies. One such place is the Thousand Islands in the St. Lawrence River. One day I was sailing down this river among the Thousand Islands, and the acquaintanceship of a small and unusually delicate kind of May-fly was forced on me by the hundreds of them that persisted in alighting on my clothes, my hat, and my hair. They kept walking unsteadily about over my face and hands and the open pages of the book I was trying to read. And they kept dying, dying, all around. One would light on the outer edge of the page, and before it had walked across to the beginning of a sentence, it would die and its body would slide gently down into the back of the book and—be a bookmarker!"
"That's not a very nice way to talk about the poor little dead May-flies," said Mary, rather seriously.
"It isn't, Mary, I know," said I. "But we've got to relieve the gloom of this tale someway, don't you think? There is too much wholesale death in it to suit my publisher! And so I am trying to introduce a little jocularity into it, don't you see, Mary?"
"People are not supposed to be very funny at funerals," said Mary, severely. "Where did the little Thousand Islands May-flies come from, and why do the people there want to know about them?"
"Because there are so many May-flies that they are a great pest. Not by eating crops—for there aren't any, I suppose, and the May-flies don't eat anything anyway—nor by carrying malaria, but just by living and dying all over; everywhere in one's summer cottage, down on the river-bank where you are watching the sunset, under the trees when you are lying in your hammock and trying to read, in your rowboat when you are paddling about to visit your neighbors on other islands. To be walked on and died on by hundreds and hundreds of little flies, and all the time, grows to be very uncomfortable. So the May-flies or river-flies or lake-flies as they are variously called are cordially hated by all the Thousand-Islanders and the St. Lawrence-Riverers. And the people want to know about where they come from, and how they live, and all about them, indeed, so as to try to find some way to be rid of them."
"And do you know where they come from, and how they live, and all about them," asks Mary, with a slightly roguish manner, I fear.
"Well, I know something. In the first place, after the dance of death, the few that don't die fly out over the lake or river or pond and drop a lot of little eggs into it. Then they die happy—if May-flies can be happy. Mind you, I don't say they can. We are the only animals that we know can be happy. And we mostly aren't. From the eggs hatch young May-flies without wings or long thread-like tails, but just little, flat, under-water creatures with gills along the sides so they can breathe without coming up to the surface. Some kinds burrow into the mud at the bottom, some kinds make little tubes or cases in which to live, while others stay mostly on the under side of stones. They eat little water-plants or broken-up stuff they find in the water, although some eat other little live animals, even other young May-flies. And many of them get eaten themselves. They are favorite food of the under-water dragons. You remember, don't you, Mary, how our dragons of Lagunita would snap up the young May-flies in Monday Pond?
"Well, these young May-flies—the ones that don't get eaten by dragons, stone-flies, water-tigers, and other May-flies—grow larger slowly, and wing-pads begin to grow on their backs. In a year, maybe, or two years for some kinds, they are ready for their great change. And this comes very suddenly. Some late afternoon or early evening thousands of young May-flies of the same kind, living in the same lake or river, swim up to the surface of the water, and, after resting there a few moments, suddenly split their skin along the back of the head and perhaps a little way farther along the back, and like a flash squirm out of this old skin, spread out their gauzy wings and fly away. They do this so quickly that your eye can hardly follow the performance."
"And then they all fly to the light and begin their dance of death," breaks in Mary.
"No, wait; they are not yet quite ready for that. First, they do a very unusual thing; something that no other kinds of insects have ever been seen to do. This is it: They fly away to a plant or bush or tree at the water's edge, and there they cling for a little while and then cast their skin again."