"But you won't admit that it is final?"

"Surely it might be a coincidence, or this American may have seen
a picture of the kind and carried it in his memory. It would be
likely to recur to a man in a delirium."

"Very good," said the Professor, indulgently; "we leave it at that.
I will now ask you to look at this bone." He handed over the one
which he had already described as part of the dead man's possessions.
It was about six inches long, and thicker than my thumb, with some
indications of dried cartilage at one end of it.

"To what known creature does that bone belong?" asked the Professor.

I examined it with care and tried to recall some half-
forgotten knowledge.

"It might be a very thick human collar-bone," I said.

My companion waved his hand in contemptuous deprecation.

"The human collar-bone is curved. This is straight. There is a
groove upon its surface showing that a great tendon played across
it, which could not be the case with a clavicle."

"Then I must confess that I don't know what it is."

"You need not be ashamed to expose your ignorance, for I don't
suppose the whole South Kensington staff could give a name to it."