“Oh, there is a garage on the premises, though I have no car. You may keep yours there if you like.”

“Fine!” said Jerry.

For the time being they left the machine in the road, and proceeded up the gravel walk. Jerry noticed that the professor seemed to be hobbling in a peculiar manner.

“Did you hurt your feet in the swamp?” the tall lad asked.

“Hurt my feet? No, not that I know of. Ah—I see! Bless my soul! I’ve forgotten to put on my shoes that I took off to dry. I was wondering what hurt me.”

Jerry had hard work to keep from roaring with laughter. For the professor, in his socks, was walking over the sharp gravel, carrying his shoes and overshoes in one hand, and his butterfly net in the other. His face was a picture as he looked down at his feet in the illumination of the incandescent lamp on his front porch.

“Bless my soul!” he murmured again. “I am getting very forgetful, I’m afraid.”

“He’s not getting it—he’s got it!” murmured Bob.

“Come in, boys, come in!” went on the professor, as he stepped off the gravel to the softer grass. “We’ll have a nice supper and a long talk.”