XLV
Nature’s Repair Shop
Of course, we get hurt in all sorts of ways—cuts, bruises, barked shins, black eyes, once in a while a bad sprain or a broken bone. Then the white corpuscles that are in our blood, and the growing life-stuff or protoplasm which is in our flesh and bones, and all this wonderful and mysterious life that is in us, take us in hand to mend us up. The same power that made us, and that keeps us alive, heals also our hurts. By and by, if we take care of ourselves, we are once more as good as new.
The small and weak and lowly creatures, which cannot take care of themselves as we can, and so are all the time getting into all sorts of trouble, are able to repair damages even better than we. The world is full of timid animals, which have neither teeth and claws to fight with, nor armor for their defence, nor speed of foot or cunning of brain with which to escape their enemies. But to make up in part for this lack, many of these simple beings seem not to mind at all such injuries as would cripple us for life; while they recover completely, and that within a few days, from accidents which would mean instant death to us.
A tiny lizard, for example, may at any moment have to scamper for his life in search of an equally tiny crack in the rock, where it may take refuge from some larger animal which wants it for breakfast. Naturally, oftentimes, the lizard so hardly escapes being “it,” that just as he whisks into safety, his pursuer snaps off his entire tail.
A loss like this would kill most larger animals, but not the lizard. He simply waits round for a week or two while a new tail grows, just as good as the old one, so that he is as well off as before. The same lizard has been known to lose his tail a dozen or twenty times, and each time to grow a new one. Since, therefore, a lizard’s tail is longer than his body, and nearly as large round, the animal must have grown enough new flesh to make at least five or six whole new lizards. Curiously however, the new tails, tho they look exactly like the old one, always have a rod of gristle or cartilage inside, in place of the regular backbone.
So too, with legs. A lizard that has had a leg bitten off, straightway grows a new one. He will even grow a whole new eye, when something happens to the one with which he happened to be born.
Yet oddly enough, the lizard, when he grows new legs and tails is continually liable to make the strangest mistakes. He will grow a new tail, when he hasn’t lost the old one, but only had a bite taken out of it. Then he has two tails. Sometimes he makes even a worse break than this, and grows out two new tails to replace the single one which after all he didn’t quite lose. Then he has three tails, which is at least one more than any proper lizard ought to possess.
It is the same, too, with legs. The lizard seems to get an idea that his leg has been bitten off, when it has only had a piece taken out of it. So he goes ahead to grow a new leg, and as a result, has five. In fact, it is quite possible, to manufacture a lizard, perfectly healthy and apparently happy, with eight legs and three or four tails.
Perhaps you have heard that “the early bird catches the worm.” If so, did you ever consider the transaction from the side of the worm? If the worm happens to be retiring into his hole just as the hungry robin catches sight of him, there is likely to be a tug of war between the eater and the breakfast. The worm swells out the front end of his body, and gets a grip on the sides of its hole, while the bird digs its claws into the ground. Sometimes the worm lets go, and gets eaten up. Sometimes he gets pulled in halves, and only the rear end goes down the robin’s red lane.
The worm minds being pulled in halves just about as much as a train of cars minds getting uncoupled. The front end calmly crawls away into its hole, goes on eating dirt as usual, and pretty soon grows itself a new tail as before.