A well-known children’s adventure story tells about a technique used by a ninja to improve jumping skills. The learning ninja plants a batch of hemp. He begins training and endeavours to leap over it everyday. At first this is no challenge, but the hemp grows quickly everyday and so does the diligent ninja’s jumping ability. By the end of the season, the warrior can allegedly clear the full gorwn stand of hemp. This certainly attests as much for hemp’s vitality as the ninja’s leaping ability.