But these creatures do not only want to be able to see their victims on a dark night; they also want to be able to creep up to them without making the slightest sound. It would be quite useless, for instance, for a lion to chase a deer, because the deer is by far the swifter animal of the two. If the lion is to catch the deer at all he must spring upon it unawares, and strike it down before it knows its danger. And this is not at all easy, for the ears of a deer are very sharp, and if the lion were to make the least noise while creeping up, it would take the alarm directly. But under his great broad paws the lion has soft, fleshy cushions, which enable him to walk along without making any noise at all. Haven't you noticed how silent a cat's tread is? You simply cannot hear her place her foot upon the ground. Well, lions and tigers walk in just the same noiseless manner, so that the deer never hears them creeping up, and is struck down and killed before it has time to realize its danger. [Illustration: FOUR GREAT CATS 1. Lion and Lioness. 2. Canada Lynx. 3. Cheeta. 4. Tiger.] But suppose that there are bushes in the way. Suppose, for example, that in order to approach the deer at all the lion must creep through a thicket. Is he not quite sure to brush up against a branch as he does so, causing the leaves to rustle? And will not the deer hear the sound and take the alarm? Well, no doubt this would happen if the lion had to depend for his silent approach only on the soft cushions under his feet. But then, you see, he has whiskers as well! Perhaps you thought these were only meant for ornament. But they are meant for use; and they are employed in a very curious manner. When they are spread out on either side, they measure from tip to tip exactly the width of the body. Besides this, there is a very delicate sensitive nerve at the root of every whisker, which runs straight to the brain. So, you see, if the tip of a whisker is touched, the brain feels it directly; and if as the lion is creeping through the bushes his outspread whiskers brush against the branches, he knows at once that there is no room for him to pass without making a noise and alarming his victim. So he draws his head back, and creeps up by another way. KILLING AND EATING Then it is very important that his claws should be kept sharp; for he depends upon them for tearing his victim down. So every claw fits into a sheath, which protects the point, and prevents it from being worn down by rubbing against the ground. You can easily see these sheaths by examining the paw of a cat; and those of the lion and tiger are formed in just the same way. And the muscles which work them are so arranged that they keep the claws always drawn back, except just when the animal uses its paw in striking.