“After his man had told me the story I had a feeling that the murder was committed by either a Sicilian laborer on the links or a negro waiter at the club.  Well, to make a short story shorter, I decided to test the blood-stain.  Probably you didn’t know it, but the Carnegie Institution has just published a minute, careful, and dry study of the blood of human beings and of animals.  In fact, they have been able to reclassify the whole animal kingdom on this basis, and have made some most surprising additions to our knowledge of evolution.  Now I don’t propose to bore you with the details of the tests, but one of the things they showed was that the blood of a certain branch of the human race gives a reaction much like the blood of a certain group of monkeys, the chimpanzees, while the blood of another branch gives a reaction like that of the gorilla.  Of course there’s lots more to it, but this is all that need concern us now.

“I tried the tests.  The blood on the handkerchief conformed strictly to the latter test.  Now the gorilla was, of course, out of the question—­this was no Rue Morgue murder.  Therefore it was the negro waiter.”

“But,” I interrupted, “the negro offered a perfect alibi at the start, and—­”

“No buts, Walter.  Here’s a telegram I received at dinner:  ’Congratulations.  Confronted Jackson your evidence as wired.  Confessed.’”

“Well, Craig, I take off my hat to you,” I exclaimed.  “Next you’ll be solving this Kerr Parker case for sure.”

“I would take a hand in it if they’d let me,” said he simply.

That night, without saying anything, I sauntered down to the imposing new police building amid the squalor of Center Street.  They were very busy at headquarters, but having once had that assignment for the Star, I had no trouble in getting in.  Inspector Barney O’Connor of the Central Office carefully shifted a cigar from corner to corner of his mouth as I poured forth my suggestion to him.

“Well, Jameson,” he said at length, “do you think this professor fellow is the goods?”

I didn’t mince matters in my opinion of Kennedy.  I told him of the Price case and showed him a copy of the telegram.  That settled it.

“Can you bring him down here to-night?” he asked quickly.

I reached for the telephone, found Craig in his laboratory finally, and in less than an hour he was in the office.

“This is a most baffling case, Professor Kennedy, this case of Kerr Parker,” said the inspector, launching at once into his subject.  “Here is a broker heavily interested in Mexican rubber.  It looks like a good thing—­plantations right in the same territory as those of the Rubber Trust.  Now in addition to that he is branching out into coastwise steamship lines; another man associated with him is heavily engaged in a railway scheme for the United States down into Mexico.  Altogether the steamships and railroads are tapping rubber, oil, copper, and I don’t know what other regions.  Here in New York they have been pyramiding stocks, borrowing money from two trust companies which they control.  It’s a lovely scheme—­you’ve read about it, I suppose.  Also you’ve read that it comes into competition with a certain group of capitalists whom we will call ‘the System.’