of how the stone has disappeared, he
stubbornly refuses to allow them to search his clothes. The effect
upon the other guests may easily be imagined. Later, however, one of
the guests having followed him home, it is discovered that the poor
old man has merely filled his pockets with different delicacies from
the table, and has taken them home to his sick grandchild.
Subsequently it is discovered that the Hindoo servant has taken the
jewel, and he is arrested and punished. In the moment that the
attention of the guests was directed elsewhere, after the old
gentleman had laid it on the table, the servant had snatched up the
jewel and dropped it into a half-filled water glass, where it remained
undiscovered while the servant was searched with the others. It is
pretty generally known that an unset pure diamond, if dropped into a
glass of water, becomes invisible.

Some time during 1911, one of the producing companies released a
picture entitled "The Class Reunion." To get the plot of the photoplay
story, simply substitute an impecunious professor for the old
gentleman in the short-story. Instead of the Hindoo servant, have one
of the pupils--if our memory serves--turn out to be the thief, and
have him drop the jewel--which is a ruby, and not a diamond--into a
glass of red wine instead of into a glass of water. In all other
particulars the two stories were identical.

Only a few months later, this plot cropped up again--in fiction
form--in a prominent American magazine. Then, in the release of
another well-known company, of January 13, 1913, it again did service
in the photoplay "The Thirteenth Man," where the inevitable banquet is
the annual reunion of "The Thirteen Club." The theme has now become so
hackneyed that, as the list given in Chapter XVI shows, it is no
longer serviceable for photoplay purposes.

Obviously, these facts are cited not to discredit the companies
referred to, but solely to emphasize the difference between the
genuinely new twist as exemplified in Conan Doyle's "The New
Catacomb," and the dangerously close similarity as exhibited in at
least one of the two photoplays just referred to as following the plot
of the _Strand_ story.

It must not be inferred, however, that all cases in which the themes
of short-stories are developed into photoplays with very little change
are plagiarisms, either conscious or unconscious. Many important
companies are negotiating constantly with the magazines for the ri