16. HELODERMA 475 



followed by gradual paralysis. These cardiac effects are 

 probably due to local action of the poison. 



4. — The vasomotor center shows no evidence of pri- 

 mary stimulation, but injection is immediately followed by 

 a great fall in blood pressure. 



5. — The great primary fall in arterial pressure is due 

 to vascular dilatation — the central or peripheral origin of 

 which has not been clearly shown. The gradual secondary 

 fall is caused by cardiac failure. 



6. — The motor nerves, with their cells and end organs, 

 remain entirely unaffected. 



7. — The sensory apparatus suffers an increase in irrita- 

 bility followed by a total loss. These changes proceed 

 from behind forward, and are of central origin. 



8. — Coagulation of the blood is at first accelerated, then 

 retarded. Serious thrombosis may occur. The blood may 

 be rendered incoagulable. 



9. — The red corpuscles are often caused to become 

 spherical, and the blood, at least outside the body, may be 

 laked. 



1 0. — Death usually results from paralysis of the res- 

 piratory centers, but when artificial respiration is main- 

 tained death supervenes as the result of cardiac failure. 

 Thrombosis must be regarded as a possible cause of death. 



1 1 . — The secretion of urine is stopped. Frequent mic- 

 turition is caused by the slow contraction of the bladder. 



12. — QEdema and slight extravasation are sometimes, 

 though very rarely, caused by Heloderma venom. 



In walking, the Gila Monster proceeds slowly, and ap- 

 pears rather awkward, but in spite of its clumsy form it 

 sometimes climbs bushes, probably in search of birds' eggs, 

 which, together with young rodents, reptile eggs, etc., form 

 its food. In confinement this lizard may be kept for years 

 upon a diet of hens eggs. It is very fond of water. 



