THE GILA MONSTER. 



{Heloderma suspectum). 



The reptile fauna of the North Amer- 

 ican continent includes a curious lizard 

 known as Gila Monster, in science called 

 Heloderma. It represents a family all 

 to itself, with only two species : Heloder- 

 ma horridum and Heloderma suspectum. 



Francisco Hernandez, a Spanish phy- 

 sician and naturalist, was the first to know 

 of its existence when he found it in Mex- 

 ico in the year 165 1. In an account of his 

 explorations he mentions a lizard three 

 feet long, with a thick-set body, covered 

 with wart-like skin, gaudily colored in or- 

 ange and black, and generally of such 

 horrid appearance that Wiegmann, an- 

 other scientist, two hundred years later, 

 called it Heloderma horridum. 



For a long time this name was given in- 

 discriminately to all lizards of this kind, 

 living either south or north of the boun- 

 dary line of Mexico and the United States, 

 till Professor Cope discovered a difference 

 between them and called the variety found 

 in our southwestern territories and states 

 Heloderma suspectum. 



Many other naturalists have since taken 

 up the study of this interesting reptile. 

 The result of their observations and ex- 

 periments was that they all agree in ac- 

 knowledging the Heloderma as the only 

 poisonous lizard in existence, although 

 their opinions are at variance as to the 

 effect of its venom on the human system. 

 Dr. van Denburgh in his latest researches 

 has found two glands, one on each side of 

 the lower jaw, located between the skin 

 and the bone. Such a venom-producing 

 gland being taken out of its enveloping 

 membrane proves to be not a single body, 

 but an agglomeration of several small 

 ones, differing in size, and each emptying 

 through a separate duct. These glands 

 are not directly communicated to the 

 teeth. When the animal is highly irrita- 

 ted, caused by constant teasing or rough 

 handling or by being trodden upon, the 

 poison is emitted by the glands, gathers 



on the floor of the mouth, where it mixes 

 with the saliva, and is transmitted through 

 the bite. 



A Heloderma has no fangs, but a good- 

 ly number of sharp, pointed teeth, both on 

 the upper and lower jaws. They are 

 curved backward and about an eighth of 

 an inch long, or even less than that. The 

 principal characteristic of these teeth is 

 that they are grooved, facilitating thus the 

 flow of the venom into the wound. It 

 bites with an extremely swift dash, di- 

 rected sideways, and holds on tenacious- 

 ly to whatever is seized with its powerful 

 jaws. Sumichrast says when the reptile 

 bites it throws itself on its back, but none 

 of the later naturalists makes mention of 

 this peculiarity. 



The venom of the Gila Monster injected 

 into the veins and arteries of smaller ani- 

 mals as rats, cavies and rabbits and into 

 the breast of pigeons and chickens, causes 

 death within twenty seconds to seven min- 

 utes. Brehm relates that a young Helo- 

 derma, and in poor physical condition be- 

 sides, was induced to bite the leg of a 

 large, well-fed cat, which did not die, but 

 gave signs of prolonged terrible suffer- 

 ings. It became dull and emaciated and 

 never regained its former good spirits. 



Among several cases of Gila Monster 

 bites inflicted on human beings can be 

 quoted that of Dr. Shufeldt, who, in "The 

 AmericanNaturalist, ,, gave an interesting 

 account of the sensations he experienced. 

 It is sufficient to say that the pain, start- 

 ing from a wound on the right thumb, 

 went like an electric shock through the 

 whole body and was so severe as to cause 

 the victim to faint. Immediate treatment 

 prevented more serious consequences. 

 The Doctor, nevertheless, was a very sick 

 man for several days and began to re- 

 cover only after a week had elapsed. 



The constituents of the venom are as 

 yet not thoroughly known, but it is said 

 to be of an alkaline nature, the opposite 



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