Revelation, Rationality, Knowledge & Truth — Page 534
ORGANIC SYSTEMS AND EVOLUTION their flight in accordance with the contours, or rocks and their undulating surfaces. They never strike their heads against other bats or protrusions, barring some very rare accidents. They can perceive a thread thinner than a hair and avoid collision. All this is done with signals, their frequencies and pitches, entirely at the command of acoustic bats. . When necessary, some bats can emit 200 clicks per second, each lasting only one thousandth of a second but kept apart sufficiently from other similar signals so that the internal make and break system constantly keeps pace with it. Within one thousandth of a second the contact of the bone, the counterpart of ossicles in humans, is broken from the eardrum and before the signal arrives back as echo it is made again, never failing within this extremely short space of time. All this is intentional. The bat knows how to raise the frequency of signals, fully commanding their pitches and changing them exactly, as needed. It can choose the frequency which does not interfere with other hundreds of thousands of bat signals. One really wonders how the hand of natural selection could have shaped the ears, the throats and the brains of the bats with such profound precision and such complete harmony. If a man happens to be there, the clicks may not be heard by him at all. Most of them are at a pitch which cannot be heard by human ears. All this profusion of sound signals if audible to man would explode his eardrums, yet luckily, all that he perceives is perfect silence in a jungle full of bats. . The disuse of eyes over a very long period of time has a shrivelling effect, like a human limb when it is not used for years is rendered useless. Prolonged effect of disuse will always continue to shrivel an organ until it becomes smaller and smaller, and may finally become obliterated. This phenomenon is common to life and spares nothing. Thus 503