man of science, basing his knowledge of lizard nature on the exact
knowledge to hand, would have hesitated in rejecting the story as, at
least, improbable. Yet it is clear that the stories of the New World
may have had an actual basis of fact; for the _Heloderma horridum_ has
been, beyond doubt, proved to be poisonous in as high a degree as a
cobra or a rattlesnake.

"At first the lizard was freely handled by those in charge at Regent's
Park, and being a lizard, was regarded as harmless. It was certainly
dull and inactive, a result probably due to its long voyage and to the
want of food. Thanks, however, to the examination of Dr. Gunther, of
the British Museum, and to actual experiment, we now know that
_Heloderma_ will require in future to be classed among the deadly
enemies of other animals. Examining its mouth, Dr. Gunther found that
its teeth formed a literal series of poison fangs. Each tooth,
apparently, possesses a poison gland; and lizards, it may be added,
are plentifully supplied with these organs as a rule. Experimenting
upon the virulence of the poison, _Heloderma_ was made to bite a frog
and a guinea pig. The frog died in one minute, and the guinea-pig in
three. The virus required to produce these effects must be of
singularly acute and powerful nature. It is to be hoped that no case
of human misadventure at the teeth of _Heloderma_ may happen. There
can be no question, judging from the analogy of serpent-bite, that the
poison of the lizard would affect man."

[Illustration: HELODERMA HORRIDUM, OR GILA MONSTER]

In an article in the London _Field_, Mr. W.B. Tegetmeier states that
this remarkable lizard was first described in the _Isis_, in 1829, by
the German naturalist Wiegmann, who gave it the name it bears, and