The Beaded Lizards 



however, a vigorous bite has been inflicted, the consequent phe- 

 nomena have proven the venomous character beyond any doubt, 

 and the hypodermic application of the pure saliva in sufficient 

 doses has invariably proved fatal to the animals experimented 

 upon rabbits, mice and frogs. 



"The first effect of the injection an inability to sit or stand 

 is manifested after a short time, about ten to fifteen minutes in 

 frogs, thirty minutes in rabbits. A certain drowsiness, similar 

 to a narcosis, overpowers the animal; paralysis and insensibility 

 seem to proceed from behind forward. The respiration is not 

 laboured, but becomes gradually slower and superficial until the 

 animal expires after a few hours with some hardly noticeable 

 twitchings. The heart has first a period of increased activity, 

 which is followed by gradual paralysis and a great fall of arterial 

 pressure, due to vascular dilatation. While these symptoms 

 appear after a small dose of venom, large doses seem to act directly 

 upon the heart muscle, the animals dying within ten to twenty 

 minutes with dyspnoea and convulsions. . . . The local 

 symptoms, with rare exceptions, are entirely wanting; it is even 

 difficult to find the spot where the venom has been injected. Yet 

 it ought not to be forgotten that a few cases of persons bitten by a 

 heloderma are on record in which extensive and painful local swell- 

 ing is noted. 



"The autopsy shows nothing but a very much dilated heart 

 and an enormous venous congestion of all internal organs. The 

 microscopical examination of the spinal cord, however, reveals 

 extensive changes in the ganglion cells of the anterior horns; in 

 fact, Baily found the changes almost identical with those de- 

 scribed as due to the action of snake venom. It is not hard to 

 believe, therefore, that snake venom and the saliva of heloderma 

 are almost identical in chemical composition. . . . 



"Treatment. It is to be expected that the persons bitten by 

 a heloderma will seldom exhibit grave symptoms, except when 

 accidentally a blood vessel has been struck directly. A treat- 

 ment after general surgical principles will suffice to subdue the 

 local phenomena, while the organism has time to overcome the 

 effects of the injected toxin. Yet a ligature ought not to be 

 omitted, and otherwise the use of anti-venomous serum should 

 be resorted to as well. The similarity of the toxins of snake 

 venom and the saliva of heloderma justifies the administration of 

 the same antidote." 



The two species of Beaded Lizards may be generally dis- 

 tinguished, as follows: 



Pink, or reddish yellow, and black. 

 Head mottled with the lighter hue. 



GILA MONSTER, H. SUSptCtUM. 



171 



