Part 94 (1/2)

READY!

'What is the use of f.a.gging like that on a hot day?' asked Harold Lock of his brother Frank, who came and flung himself panting on the gra.s.s beside him.

'I must keep in training: a fellow so soon gets slack and out of practice if he is lazy,' was the answer.

'Well, being lazy is good enough for me in the holidays,' the elder boy said. 'I should think it pretty hard lines to have to run a mile in this sun.'

'It makes all the difference, though, if you are keen,' Frank told him.

'I want to be the fastest runner in the school, and I don't want to go back and find I am easily beaten in the sports.'

'I don't see the good of it myself,' said Harold, rather scornfully, but Frank only laughed good-temperedly, and began to swing himself on a branch of the tree for change of exercise. If there was one thing he hated more than another, it was sitting still for too long a time.

The same evening the boys were on the platform of the little village station, watching some trucks being shunted from the main line on to a siding. Suddenly there was a loud cry from one of the men engaged in the work as a heavy truck got off the rails, turned over, and dragged another with it. No one was seriously hurt, but the station-master, who was soon on the scene of the accident, turned pale as he saw the obstruction on the line.

'Stop the down express!' he shouted. But the signal-box was a quarter of a mile away, and precious minutes would have pa.s.sed before he could be near enough for his voice to reach the signal-man. By that time it might be too late to stop the express.

Then, like an arrow, a nimble little figure flew past him. It was Frank, his running powers put to some practical use at last. The station-master followed as quickly as he could. But when at last he came up breathless, he found that Frank had already done his work, and the signal was against the train.

'It's touch-and-go whether we have caught her,' muttered the signal-man, and they all held their breath as the rumble of the train was heard in the distance.

'She's slowing down--she's safe!' gasped the station-master, and he hurried down again, followed by Frank and the signal-man.

But it was only a few yards off the overturned trucks that the express was finally brought to a standstill. The few seconds gained by Frank's speed had saved her. Nothing could have prevented a terrible accident if the signal had not caused the train to slow down just in time.

The pa.s.sengers crowded round Frank, and thanked him warmly when they heard the story, and a few days later came a more practical expression of their grat.i.tude in the shape of a handsome gold watch.

'So your running was some good after all,' Harold said, and he no longer laughed at his small brother's hobby, but learned to admire the nimbleness of body which, with his ready wit, made him of so much use in an emergency.

M. H.

INSECT WAYS AND MEANS.

IX.--THE EARS AND NOSES OF INSECTS.

Most of us have a vague idea that what we call the 'ear' is only partly concerned with the work of hearing; but only a few know exactly what a complicated organ the ear, as a whole, really is. The external 'ear'

only serves as an aid to the collection of sounds, and the real work of hearing is performed by a delicate organ inside the head. Seals, moles, whales, and porpoises, birds, reptiles, and fishes have no visible ear; yet we know that they are not deaf, though in many the hearing must be dull. In all these creatures the sense of hearing lies inside the head.

But the ears of insects must be looked for in strange places indeed, and, when found, they seem to bear no sort of likeness to what most of us call ears. They may be on the antennae, on the trunk, or on the legs!

In the gra.s.shopper, for example (fig. 1), the ear is placed on the abdomen, just above the base of the great hind-leg, so that this leg must be pulled down before the ear can be seen. When this has been done, there will be found an oval drumhead-like spot (figs. 2 and 3); this is the outer surface of the ear. If you had sufficient skill to take away this part of the body, so as to show the inside of this drum, you would find two horn-like stalks, to each of which is fastened a small and very delicate flask, with a long neck. This is filled with a clear fluid, and corresponds to a similar structure within our own ears.

In the green gra.s.shoppers--those delightful sprites of hot summer days--'ears' of a precisely similar structure are found on the fore-leg instead of on the body.

In a little gnat-like insect known as Corethra, common in England during the summer months, the 'ear' takes the form of delicate hairs growing out from the body on a stem, like the teeth of a comb; the base of what corresponds to the back of the comb is connected with a delicate nerve, and this, as in the case of the similar nerve in the gra.s.shopper and locust, makes hearing possible.

Only in some ants and bees, and in some mosquitoes, is the organ of hearing placed on the head. We say _on_, rather than _in_, the head, because it is formed by a modification of part of the antennae. A German naturalist, named Mayer, performed an experiment to prove that the hairs on these antennae can be made to vibrate by means of a tuning-fork. Only those hairs which have to do with the production of sound answered to the notes of the tuning-fork, and these vibrated at the rate of five hundred and twelve vibrations per second. Other hairs vibrated to other notes, which were those of the middle octave of the piano and the next above it. Mayer also found that certain of these vibrations corresponded with the notes produced by the 'song' of the female mosquito.