so very long ago, been hospitably opened to them. But, though they waited
breathlessly for a response, none came--the house was as silent as a tomb.

"Do it again, Betty. He might be asleep or something." suggested Mollie,
with a glance over her shoulder at the quiet woodland. "Knock harder this
time."

Betty obeyed, but with no better success than the first time. Everything
was as silent as before.

"Isn't there a bell, I wonder?" suggested Amy, wishing ardently that they
were back on the road once more. "Perhaps your knock isn't loud enough for
him to hear."

"We might tap on the window," suggested Grace. "If I use my ring on the
window pane he surely ought to hear that."

She started to suit her action to the words when an exclamation from Betty
made her pause. The latter had tried the door and found to her surprise
that it gave to her touch.

"The door is unlocked," she said. "I don't believe the professor is in
here at all and if he has gone into the woods to hunt his butterflies and
beetles I am sure he wouldn't mind our going inside. What do you think?"

She was about to push the door open, but Grace detained her with a nervous
hand on her arm.

"Oh, I don't think we had better go in, Betty!" she cried. "You know what
we were speaking of in the car. Suppose we should find that he has--that