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THE LONG-EARED BAT.

beautifully transparent, and are thrown by the animal at pleasure into elegant curves. They are usually folded under the arm during sleep, especially if it be pro

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found. It is said that a person who had not seen it in the act of folding its ears, could never imagine it to be the same species when they are fully expanded.

The sense of hearing in many quadrupeds is particularly keen, and seems to be given especially to the her: bivorous tribes. The elk, though not remarkably swift, avoids its enemies by its acute sense of sound. A similar power, it is well known, is possessed by the stag. The chamois and the antelope are still more highly gifted than either of these creatures.

With the power

across

of hearing in hares and rabbits we are all acquainted. The ears of the horse demand particular notice. The internal part of the conch is covered with long hair, which stands the

passage

in
every

direction : this is to defend the ear from insects, which can only penetrate it with great difficulty. Cold air is also prevented from reaching the interior of the ear, and the sound is moderated, penetrating readily, but not violently, so as not to injure the membrane which covers the drum. The hearing of the horse is very acute. He attends to many vibrations of the air, far too slight to impress the human ear. He catches the cry of the hounds a considerable time before his rider becomes aware of the slightest sound. How absurd and cruel is the practice of cropping this part ! in itself it is perfect; to cut it is to mutilate one of the most beautiful parts of these animals. It is more intelligible than the eye; and an attentive observer can tell, it is said, “ by the expressive motion of the ears, almost all the horse thinks and means."

It is considered that ears rather small than large, placed not too far apart, and erect as well as quick in motion, show both breeding and spirit. If a horse is in the habit of carrying one ear forward, and the other backward, and especially if he does so on a journey, he

SPECIAL PROVISION FOR THE WHALE.

will generally have both spirit and continuance. The stretching of the ears in contrary directions indicates attention to what is passing around the animal, and while doing so he cannot be much fatigued, or likely soon to suffer from weariness. Few horses sleep without directing one ear forward, and the other backward, that they may hear the approach of objects in every direction. When horses or mules march in company at night, those in front direct their ears forward; those in the rear point them backward; and those in the centre laterally, or across; the whole troop appearing to be actuated by one feeling of regard to the general safety. It is a common saying, that when a horse lays his ears flat back on his neck and keeps them so, he is most assuredly meditating mischief, and the stander-by should beware of his heels or his teeth. The ears will be laid back in play, but not so decidedly, or so long. A quick change in their position, and more particularly the expression of the eye at the time, will distinguish between playfulness and vice.

A special provision is made for whales, whereby they hear either through the medium of the air they breathe, or of the water, in which they live. Let the reader consider for a moment the difficulties which are here to be overcome. The ear of a fish, having no external communication, though best adapted to receive the violent concussions conveyed through the water, could never appreciate the more delicate vibrations of the air. The common ear of the mammalia would be constantly deafened by the tumult of the waters. What, then, shall be done ? The wisdom of God has furnished the reply. The outer opening of the ear is made as small as possible, and this part only is exposed to receive aquatic sounds. The eustachian tube, on the contrary, is very large, and opens into the blow-hole, through which the whale respires atmospheric air. When, therefore, the creature comes to the top of the water to breathe, it is this that conveys aërial sounds to the ear, and thus it hears sufficiently in both conditions. How admirable are the arrangements at which we have thus rapidly glanced !

Above the earth, around the sky,
There's not a spot, or deep, or high,
Where the Creator has not trod,

And left the foot-prints of a God. In returning from this survey of inferior creatures, to man, his sense of hearing appears most admirably adapted to his knowledge and delight. The power with which the human ear is gifted may well fill us with astonishment. Allusion has already been made to a thin plate of tempered steel made fast at one end, and

MUSICAL SOUND.

the other being drawn aside. On this being done, it has been proved that the plate begins to sound when there are thirty-two vibrations in a second, and at this rate of movement the sound which it gives is of the same pitch as that of an organ pipe, open at both ends, and thirty-two feet in length. By vibration is meant, in this instance, the passage of the plate from the extreme excursion on one side of the point of rest to the opposite. The velocity at which sound ceases to be appreciable is not so easily determined. Until recently, it was usual to fix it at 8200 vibrations, but it has been discovered that acute sounds may be distinguished at a velocity of 24000 vibrations in a second. It is possible that the limit may be considerably beyond that number.

It is by a sense so exquisite that we derive pleasure from the melodies of nature and of art. What observer of nature has not been delighted with the song of the lark, which has been said, from its admirable structure, to convert the atmosphere into a musical instrument of many stops ?” That bird can produce an exceedingly wild and varied song, a song which, though not equal in power

and

compass to that of many warblers, is more varied in the whole succession.

A number of single and separate sounds following one another in quick succession, produce a continued

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