Читать книгу Natural History - Francis L. Hawks - Страница 3

Table of Contents

Uncle Philip tells the Children about a Fly that can work with a Saw and a Rasp, like the Carpenter.

"Well, boys, this is a beautiful day. The sun is shining brightly, and the birds are singing, and the insects are flying about, and the grass is green, and every thing appears pleasant, and you feel happy too, and have come, I suppose, to see old Uncle Philip."

"Yes, Uncle Philip, we are tired of playing now, and so we have come to ask you to talk with us, and tell us about some of the curious things you know."

"Well, boys, I will tell you about some very strange things. I will talk to you about animals that know how to work with tools like a man."

"Work with tools, Uncle Philip! That is strange; but we know it is so, if you say so; because you will not tell us any stories but true ones. But where do they get the tools?"

"Ah, boys, 'the hand that made them is divine!' They get them where we get all that is useful and good,—from God. The Bible says that He 'is wise in heart, and wonderful in working;' and he has made many a poor little insect, and given it tools to work with for its comfort, as good and perfect as any that man can make. Yes, these poor little creatures had tools long before man had. God cares for the insects, boys, as well as for us."

"But, Uncle Philip, what sort of tools do you mean? Tell us about them."

"Very well, I will; do you think of some kind of tools that men use: think of the carpenter and his tools, and let us see if we cannot find some of them among the insects."

"Why, the carpenter has a saw. Is there any saw among these little fellows?"

"Yes indeed, there is; and a capital saw it is. Now listen, and I will tell you all about it. There is a kind of fly called the saw-fly; it has four wings, and commonly its body is yellow, and its head is black; but the most curious part of it is the saw. The young ones feed upon the leaves of rose-bushes, and gooseberries, and raspberries, and currants, and several other kinds of bushes; and the old ones always lay their eggs on the branches of these bushes, so that the young ones may have something to eat as soon as they come out. It uses its saw to make a place in the branch to put its egg in."

"Uncle Philip, what is the saw made of?"

"It is made of something like horn, and is fixed very nicely in a case; it resembles what the cabinet-makers call a tenon-saw more than it does the carpenter's common saw. The tenon-saw is made of a thin plate of steel, and has a stiff brass back, to keep it from bending. The brass back has a groove in it, and the saw is put in that groove, and then it is fastened to it. But the fly's saw is fixed in another way: there is a back to it too, but that back is not fastened to the saw. The groove is in the saw, and there is a ridge all along the back-piece, which just fits in the groove, and so the saw slides backwards and forwards, and the ridge always keeps it in its place. Besides all this, boys, the fly is better off than the cabinet-maker, for he uses only one saw at a time; but our little workman has two exactly alike, and they are so fixed that the creature first pushes out one, and when it is drawing that back, pushes out the other; so that it is all the time cutting, and does double work. I think the fly's saw is the best, too, for another reason. The saws of the carpenter and cabinet-maker have their teeth bent; first, one a little on one side, and then the next to it a little on the other side, and so on to the end of the saw; so that when sawing, the cut may be wide enough for the blade to move easily. Now the fly's saw has the teeth a little bent, or twisted, too; but it has something else: on the outside of every tooth there are a great many very small teeth, so that the outside of every one is just like a rasp, or file."

"But, Uncle Philip, it must take them a great while to saw a very little cut; they are so small."

"Yes, it does; but they persevere. It takes them more than an hour and a half to make one groove, and sometimes they will go on and make as many as six without stopping. That shows, boys, what perseverance will do."

"And when it is done sawing, Uncle Philip, where does it keep its saws?"

"Oh, I told you they fitted in a case; but when the fly is done sawing, it uses the saws to put the egg in the place cut for it, and then it draws the saws almost entirely into the case, and drops upon the egg a sort of frothy stuff like a drop of soap-lather."

"What is that for?"

"I suppose it is to glue the egg fast, or else to keep the juices in the bush from hurting it."

"Well, this is a curious fly, Uncle Philip."

"It is strange, boys, because you never heard of it before; but it is a cunning fly, as well as a curious one."

"What does it do, Uncle Philip?"

"Why, when it is frightened, it will fold up its case and saws under its body, and draw up its legs, and pretend to be dead; and then it will not move, even if you stick a pin through it."

"Can you tell us any thing more about this fly?"

"Nothing very strange, boys; but we have found out two tools, I think, a saw and a rasp, and that is enough for one poor little fly to give us. Here, boys, are pictures of these saws; I have made them a great deal larger than they are in the fly, so that you can see them plainly."

Saw of the Saw-fly, with Rasps shown in the Cross-lines.

Portion of the Saw-fly's comb-toothed Rasp, and Saw.