Just so again. The root has a brain, too, or what answers for a brain. And the root's brain, is in its head; at least in the vicinity of its nose—that is to say, its tip. It's the tip that first finds out which side of the road is best, and passes the word back to the part of the root just behind it to bend this way or that. It's also the tip that feels the pull of gravity and knows that it's the business of roots to keep under cover. And Mr. Root just will have it that way! You can't change his mind. Mr. Darwin tried it and he couldn't; although he finally changed human people's minds a lot.
WHERE MR. ROOT
WEARS HIS CAP
A root wears its cap right where you do—over its brain department; that is to say, the tip. It is called the "root cap" and protects the tip from injury.
This is how he tried it on a root. He took a bean with a little root that had just started out into the world. He cut off the tip and then set the bean so that the root stuck straight up. It continued to grow that way for some little time. Finally, however, a new tip had formed. Then there was a general waking up, as if the tip said to the rest of the root:
"Here, here, this will never do! Where are you going? You must bend down!"
Anyhow that's what the root proceeded to do. One side seemed to stop growing, almost, while the other side grew rapidly and so the bending was done.
"Did you ever! But how does the tip send back word?"
"Don't ask me!" says the science man; say all the science men, even to this day. "We don't know yet just how it's done. But we're studying these things all the time, and we'll know more about it by and by. Meanwhile, perhaps you'll tell us why you say 'ouch' and pull your finger away when you touch something hot."