"How does this creature walk?" asked the crab-like one.
"By means of long tubes which it projects at pleasure."
"How do the tubes enable the creature to walk?"
"They have suckers on them."
"What are the suckers like?"
"They are round hollow discs."
"Are you sure they are round?" asked the other sharply.
"Yes," said Tom stoutly, though his ideas on the subject were rather vague."
"And how does this sucker act?" asked the taller examiner.
Tom began to feel that these two men were exhibiting a very unseemly curiosity. There seemed to be no satiating their desire for information. "It creates a vacuum," he cried desperately.