are reading."

I expressed some doubt as to whether the regular police were
enlightened enough to take that view of it.

"Some of them are," he replied. "Yesterday the chief of police in
a Western city sent a man East to see me about the Price murder:
you know the case?"

Indeed I did. A wealthy banker of the town had been murdered on
the road to the golf club, no one knew why or by whom. Every clue
had proved fruitless, and the list of suspects was itself so long
and so impossible as to seem most discouraging.

"He sent me a piece of a torn handkerchief with a deep
blood-stain on it," pursued Kennedy. "He said it clearly didn't
belong to the murdered man, that it indicated that the murderer
had himself been wounded in the tussle, but as yet it had proved
utterly valueless as a clue. Would I see what I could make of it?

"After his man had told me the story I had a feeling that the
murder was committed by either a Sicilian labourer 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