SALIVA OF THE GILA MONSTER. 203 
(b) If poison is present what are its physiological effects ? 
(c) What are the causes of such diversity of opinion ? 
My Heloderma was the sole survivor of eight or ten brought from Arizona in 
1892 and, although seemingly fat and healthy, was not very active. It was of moderate 
size, being about eighteen inches long. The amount of saliva obtainable from it was so 
small that it could be gathered satisfactorily only by causing the reptile to bite absorbent 
paper wrapped around a piece of soft rubber and afterwards dissolving out the saliya in 
water. For this purpose filter paper was used. 
It would not do to let the Monster bite the pigeons, because if this were done and 
the pigeons died the skeptics might justly claim that death was due to the mechanical 
injury inflicted by the powerful jaws, with their long, curved fangs, rather than to any 
poison haying been inserted. yen when the Heloderma’s saliva solution was injected 
hypodermically and death could not have been occasioned by the severity of a wound 
there might be some doubt as to the effect of a quantity of water suddenly placed under 
the skin, or it might be claimed that some substance was present in the water or the paper 
used quite poisonous enough to cause a pigeon’s death irrespective of any venom from the 
Monster. So samples of all the materials used had to be subjected to careful tests to 
show that they were harmless.* 
Mucus. 
A greater or less quantity of thick mucus is present in the back part of the mouth of 
the Gila Monster. Some of this often adheres to the filter paper in stringy masses. It 
is entirely without poisonous properties and need not be mentioned again. 
THe Porsonous SALrva. 
The water solution of saliva when extracted from the paper is a slightly yellow- 
ish or opalescent liquid, often more or less stained with blood owing to injury to the 
gums. It is faintly alkaline, and ordinarily possesses a pungent and highly characteristic 
though not unpleasant odor. This odor becomes less and less noticeable when the Monster 
is caused to bite every day, but its strength seems to be no indication of the lethal power 
of the saliva. That the solution of saliva thus obtained contains a very powerful poison 
is shown in the following experiments : 
EXPERIMENT I.—Noy. 11, 1896. The Heloderma was caused to bite on paper three times. The 
*In order to test my materials, and some other things as well, the following preliminary experiments were 
performed, the first repeatedly : 
ExPERIMENT,—A sample of filter paper was soaked in water, which was then injected subcutaneously in 
front of the wing of a pigeon. During two hours there was no effect, and the next day the bird was still well. 
EXPERIMENT,—Mixed human saliva with an equal quantity of water and injected about twenty minims in 
wing of pigeon at 12.01 P.M. No effect. Next day well. 
EXPERIMENT.—Mixed blood of horned toad (Phrynosoma frontale Van D,) with water and injected wing of 
pigeon. No effect. 
