"Miss Todd said her brother was mighty absent-minded and that quite often he forgot to tie up his shoelaces."
Mr. Hardy was interested.
"I didn't hear that one," he said. "It might be valuable. I'll make a note of it. A clue like that might mean a great deal in a case like this."
"And about 'by jing?'" asked Frank.
"By jing?"
"It's an expression he used. He never swears, but once in a while he says 'by jing!' if he is excited."
"That's something new, too. In all the information I picked up about Todham Todd I didn't hear anything about that expression or about the shoelaces, and they are two of the most important clues I could ask."
The boys were gratified that they had gained this much information for their father's benefit. They knew that although Fenton Hardy had given up the direct search for the missing professor, he would never abandon the case until there was a definite solution one way or the other.
"Have you found why he disappeared from home?" asked Joe.
"I imagine he simply lost his memory," said Mr. Hardy. "At the present time, from what information I could pick up, he has no idea that his real name is Todham Todd. His memory is completely gone and he isn't able to remember anything of his past life. Probably if he met his sister again or some old acquaintance, it might all come back to him. He is wandering around, trying to find out who he is and where he comes from."