“It certainly was,” agreed Bob.  “That man acted in a strange manner, too, as if he was afraid some one would see him.  I wonder if there is any mystery connected with him?”

There came a time when the boys had good reason to remember this incident of the box filled with a strange substance, for they were in great danger from it.

“Well, I don’t know that it concerns us,” mused Ned.  “I guess we’ll not get any damages from the railroad company in time to use the money on our California trip, so we might as well take some cash out of our saving fund.  I do wish we’d hear from the professor.  It’s several days since I wrote to him, saying we would go with him.”

“I suppose he is so busy catching a new kind of flea, or a rare specimen of mud turtle, that he has forgotten all about writing,” suggested Bob.  “If he doesn’t—­”

What Bob intended saying was interrupted by a commotion at the front door.  The bell had rung a few seconds before, and the servant maid had answered it.  Now the boys heard her voice raised in protest: 

“Stop!  Stop!” she cried.  “Don’t do that!  You are a crazy man!  I’ll call the police!”

And, in reply came these words: 

“Calm yourself, calm yourself, my dear young lady.  All I desire is to capture that spider crawling on your left arm.  It is a very valuable variety of the red spotted species, and I must have it for my collection.  Now just stand still a moment—­”

“Professor Snodgrass has arrived!” cried Ned, as he made a rush for the door.

CHAPTER VI

 A strange conversation

What the boys saw made them stop short in amazement, and they had hard work not to burst into laughter at the sight of the professor, but they knew he would be offended if they made fun of him.

Professor Uriah Snodgrass had dropped his valise on the doorstep, and the impact had caused it to open, thereby liberating a number of toads and lizards which were crawling about the steps.  In his hand the scientist held a large magnifying glass, through which he was staring at something on the arm of the servant.  She had her sleeves rolled up to her elbows, for she had been busy sweeping when she answered the door bell.

“Let me go!” cried the young woman.  “You are crazy!  I’ll call the police!”

“One moment!  One moment!” pleaded the professor eagerly.  “I must have that spider.  There!” and with a sudden motion he captured the small insect and transferred it to a tiny glass box.  “I have it!  Oh, this is a most fortunate day for me.  The museum will be very glad to get this.  It is a perfect specimen,” and he peered at it through his magnifying glass, as it crawled around, a captive in the box.

“Hello, Professor!” greeted Ned.  “Glad to see you.”

“Oh, Ned, how are you?” asked the scientist, without glancing up from his inspection of the spider.  “Luck seems to be with me as soon as I arrive at your house.  I have a spider—­”