202 SOME EXPERIMENTS WITH THE 
“This interesting and virulent heart poison contrasts strongly with the venoms of serpents, since 
they give rise to local hemorrhages, and cause death chiefly through failure of the respiration, and not 
by the heart, unless given in overwhelming doses.’’ 
For a time, it seemed that the experiments of Mitchell and Reichert had answered 
the question of the poisonous power of the Heloderma once and for all. But five years 
later, Dr. Yarrow, then Honorary Curator of the Department of Reptiles in the United 
States National Museum, performed some equally careful experiments upon rabbits and 
chickens. These, he says, 
*“ Would seem to show that a large amount: of the Heloderma saliva can be inserted into the tissues 
without producing any harm, and if, is still a mystery to the writer how Drs. Mitchell and Reichert and 
himself obtained entirely different results. Were it not for the well-known accuracy and carefulness of 
Dr. Mitchell, it might be supposed possibly that the hypodermic syringe used in his experiments contained 
a certain amount of Crotalus, or cobra venom, but under the circumstances such a hypothesis is entirely 
untenable.”’ 
Notwithstanding Yarrow’s results, Dr. Mitchell still held his original opinion in 
1889. 
The following year, Prof. Samuel Garman, of the Museum of Comparative Zoélogy 
of Haryard University, published an account of experiments in which he caused an 
active Gila Monster to bite the shayed legs of kittens without serious effect. He con- 
cludes that 
“The results of the experiments suggest danger for small animals, but little or none for larger ones. 
Large angle worms and insects seemed to die much more quickly when bitten than when cut to pieces with 
the scissors.”’ 
Thus while in England the Heloderma was unanimously held to be venomous, Dr. 
Shufeldt, in 1891, summarized American opinion as follows: 
“« Here in America the evidence would seem to be rapidly leading to the demonstration of the now 
entertained theory that the saliva of this heretofore much-dreaded reptile is possibly entirely innocuous.”’ 
“« Thus the matter seems to stand at the present time—perhaps the vast majority of physicians who 
followed Drs. Mitchell and Reichert in their experiments fully believe to-day that the bite of a ‘ Gila 
Monster’ will very often prove fatal even in the case of man; while, on the other hand, naturalists 
almost universally believe that the saliva of this saurian is hardly at all venomous, and then only under 
certain conditions. ’’ 
Il. THE MOUTH FLUIDS. 
In the winter of 1896-97 I began a series of experiments with the saliva of the Gila 
Monster, the results of which are given in the subsequent pages. My object was to 
answer the following questions : 
(a) Is the bite of the Gila Monster poisonous ? 
