120 CHAPTERS ON THE NATURAL HISTORY 



then cm the other, by the extension of the flaming ornament at 

 bin throat. 



\\'hat a very different reptile we have in our big, sluggish Gila 

 Monster (Heloderma suspectum) of the southwestern regions of 

 the United States. These large lizards, still resting, in the eyes of 

 many, under the suspicion of the charge of being venomous, I have 

 had in captivity upon several occasions, and in former years have 

 written and published a great deal about them. In Pigs. 29-31, 

 illustrating the present chapter, I reproduce some photographs 

 of a large heloderma that I had for a long time alive, and these 

 figures originally appeared in an article of mine in a New York 

 medical journal in 1891, wherein the poisonous bite of the lizard 

 was fully discussed up to date. There will also be found many 

 references to the literature of the subject, and a comparison of 

 views upon (lie poisonous or non-poisonous character of the 

 saliva of the Gila Monster. In 1890 I published, with several 

 plates, in the I'. Z. S., of London, a one-hundred page memoir 

 upon the anatomy of two species in the genus Heloderma — that 

 is, horridum and suspectum, and eight years previous to that I 

 printed in The American Naturalist an account of a severe bite I 

 had received from one of the reptiles. 



Professor E. D. Cope, when a guest at my house a number of 

 years ago, told me that these figures — that is, the ones illustrat- 

 ing this chapter — " gave a better idea of the form of a heloderma 

 than any of the many figures that had thus far been published, 

 either here or in Europe." Between systematic persecution and 

 the greed of zoological collectors, the Gila Monsters are now 

 becoming very scarce in those regions where formerly they 

 were abundant, and doubtless at the end of another half 

 century, not one will be found in nature anywhere in the terri- 

 tory of what is now called Arizona. 



While at Port Wingate, in New Mexico, I also had a photog- 

 rapher make me a picture of two live helodermas I there had at 

 the time. These are reproduced in Fig. 28; the large one is the 

 same specimen shown in Figs. 29-31, while the smaller one I 

 dissected from the London anatomical memoir. This figure gives 

 an excellent idea of how these handsome lizards appear crawling 

 over the rocks in a state of nature. Perched up on top of one of 

 the stones will also be seen a small specimen of Douglass's 

 Horned Toad (Phrynosoma douglassii). Pig helodermas may at- 

 tain a length of twenty inches, they being orange and black in 



