has, without doubt, been
using some sort of filterable virus to induce cancers, just as the
experimenters at the Rockefeller Institute have done with animals.

"Naturally, in the Moreton family, this person found a fertile soil.
Perhaps he waited until he saw what looked like a favorable wound, or
traumatism. It is well-known that cancer often can be traced to a wound.
Perhaps he introduced this virus surreptitiously into a cut, now and
then. For, experiments show that the virus is strikingly dependent for
its action on the derangement of the tissues with which it is brought in
contact.

"This person must have had a high percentage of failures in his attempts
to inoculate the virus successfully. But by persistence and taking
advantage of every predisposition afforded by nature, he succeeded. At
any rate, this person must have been intimately acquainted with the
family, must have had some motive for seeking their deaths,--for
instance the family fortune.

"It makes no difference whether the victims might have had cancer sooner
or later, anyway. Even if that were so, this cold-blooded villain was at
least hastening the development, if not actually causing the frightful
and fatal disease."

Myra Moreton shuddered, and looked at Dr. Goode anxiously as Kennedy
proceeded. He seemed about to interrupt, but managed to check himself.
Craig reached over and picked out from the satchel the hat which we had
found on a desk at the office of the cancer quack.

"In the raid of Dr. Loeb's," he explained, changing tone, "a man
disappeared. I have here a soft hat which he left behind in his hurry to
escape, as well as some of the filters he was carrying."

He turned the hat inside out. "You will see," Craig pointed out, "that
on the felt of the inside there are numerous hairs, from the head of
the wearer."

I leaned forward, breathlessly. I began to see the part I had played in
building up his case.

"Human hair," he remarked, "differs greatly. Under the microscope one
may study the oval-shaped medulla, the long pointed cortex, and the flat
cuticle cells of an individual hair. The pigment in the cortex can be
studied also.

"I have taken some of the hairs from the inside of this hat, examined,
photographed, and measured them. I have compared them with a color scale
perfected by the late Alphonse Bertillon. In fact, in France quite a
science has been built up about hair by the so-called 'pilologists.' The
German scientific cr