Kent Gardner. age 9 of Holbrook. Arizonas
Do both ends live when you cut a worm in two?
If you lose a leg or an arm it has gone for good. This is true of oats. dogs pigs and elephants But it is not true of all animals. Some animals regrow a lost arm. leg or tail. Strange to say it is certain simple! humble animals who know this useful trick.
If a starfish loses an arm he simply grows a new one. If he loses two or three of his five arms he grows new ones. Should a little salamander loose his tail he just gets busy and regrows it. Lizards are forever getting their tails pinched off. It matters not. For every lizard loan grow a new tail in a few weeks. If he looses that one it too is replaced.
And the little pink earth worm can do even better. He can grow a new head. a new tail or two new tails. This depends on just where he is sliced in two. If you look closely at Mr. Pinky you will see that his long body is ringed in sections. Count them and you will find about 150 of these segments. You can spot his head ends for that is the direction in which he crawls. If he refuses to move you can recognize his head as the narrow. more pointed end. The tail and is thick and somewhat flat.
You need to know this in order to get the best results from slicing him in two. For best results. you must slice him somewhere between the twelfth and eighteenth segments counting from the head end. After the operation Mr. Pinky will start to sprout from each out area. The tail end will in time grow up to five new segments which serve as a head. The head end may add a still larger number of segments to form a new tail. After a week or two earthworms will crawl where only one crawled before.
The worm is not so lucky if he is sliced behind his eighteenth segment. The head end will grow a tail all right. This end will be a complete worm again in a very short time. He will crawl away and go about his business as before.
But the tail end comes to no good. It seems that certain segments around number eight are necesaary to grow a head. Without them this amazing job is impossible. But the worm tries in any case„ It grows another tail from the cut end of the tail section. This produces a worm made of two tails placed end to end.
Such a headless wonder cannot long survive. It can crawl for those ringed segments move him along by expanding and contracting like a concertina. The headless wonder can even breathe. for a worm breathes through his skin. His moist skin is able to dissolve oxygen from the air. But$ of course a headless worm cannot eat. So all that trouble was wasted. The worm made from an old tail and a new tail soon perishes from lack of nourishment.
So the earthworm: it seems refuses to give up when sliced in two. Mr. Pinky cannot be destroyed this way. If the slice is in the right spot he may be better off after his operation. He may be two worms. At worst the original worm will grow the lost tails but his sliced tail section may be unable to provide him with a new head.