A scientist was conducting an important experiment in animal behavior. He first trained a frog to leap forward when he gave the command "Jump." Next, he removed one of the frog's front legs and repeated the command. The frog jumped again. Then he removed the frog's other front leg. When he repeated the command, the frog jumped once more. He repeated the experiment after removing one of the frog's back legs with the same result. Finally, he removed the frog's last leg. When he commanded it to jump, nothing happened. He summarized his findings in his journal as follows"
"When one of the frog's legs are cut off, the frog is still able to jump.
"When two of the frog's legs are cut off, the frog is still able to jump.
"When three of the frog's legs are cut off, the frog is still able to jump.
"When all four of the frog's legs are cut off, however, the frog suddenly goes deaf."