482 REPORT OF NATIONAL MUSEUM, 1898. 



of the life liistory of the Helodcrma, when Suuiichrast, a well-known naturalist 

 resident in Mexico, stated it as his opinion that it was the exception that small 

 mammals died from the hite of this saurian. 



Soon after there appeared an editorial in the American Naturalist (1882, ji. 842) 

 referring to the experiments of Ur. Irwin, of the Army, which went to prove that 

 the bite of the Heloderm was comparatively harndess; but it added, further, that a 

 specimen in the Zoological Garden of London had bitten a frog and a guinea pig, 

 both of which had died in a few moments. Still, the editor of the Naturalist Avas of 

 the opinion that "this might happen if this large lizard was not poisonous, and 

 there is room for more careful experiments as to its venomous qualities." 



In the same year no less distinguished an authority than Dr. Giinther, of the 

 British Museum, comes forward and states that there can be no doubt as to the poi- 

 sonous nature of the bite of II clod erm a horridiim, and cites numerous cases to supi)ort 

 his views; and Dr. Sclater, the secretary of the Zoological Society of London, 

 apparently entertained a similar opinion, as did also the eudnent herpetologist, Mr. 

 Boulenger, of the British Museum. 



During the same year the present writer, who was at that time connected with the 

 department of reptiles at the U. S. National Museum, was severely bitten by an 

 infuriated adult specimen of Heloderma suspectum, and although much pain and grave 

 symptoms at once supervened, the results passed entirely away in a few days with 

 barely any treatment. I published a short account of it at the time. Again, before 

 the year closed. Sir Josejih Fayrer brought forth some evidence, deduced from 

 experiments, that went to show the poisonous nature of the bite of a Heloderm. 



Early in 1883, however, the matter seemed to be definitely settled for good and 

 all, through the results obtained by the very celebrated experiments of those two 

 distinguished physicians of Philadelphia, Dr. S. Weir Mitchell and Dr. Edward T. 

 Keichert. After a most carefully conducted series of experiments with the saliva 

 taken from living Ilelodcrms, these authorities were prepared to say that it possessed 

 properties of an extremely venomous nature, killing pigeons and small mammnls a 

 few moments after they had received an injection of it hypodermically. 



Five years now elapsed with hardly a printed word appearing anywhere upon the 

 question of the poisonous or nonpoisonous qualities of the saliva of one of these 

 suspected reptiles. Then there appeared an account of the somewhat remarkable 

 series of experiments made with the saliva of living Heloderms by Dr. H. C. Yarrow 

 at the U. S. National Museum, Dr. Yarrow at the time being honorary curator of the 

 department of reptiles in that institution. This investigator's methods of procedure 

 were rather different from those adopted by Mitchell and Reichert, but apparently 

 they were conducted with equal care, and, strange to say, led to an entirely differ- 

 ent result. Some eight or nine exjieriments upon chickens and rabbits went to 

 prove that hypodermic injections of the saliva and bites of angry Heloderms were 

 by no means fatal to those animals, and practically they always recovered from the 

 effects of the same. After presenting the steps of his linal trial, this author con- 

 cludes his account with the following remarks: "This experiment would seem to 

 show that a large amount of the Heloderm saliva can be inserted into the tissues 

 without producing any harm, and it is still a mystery to the writer how Dr. Mitchell 

 and Dr. Reichert obtained entirely different results. Were it not for the well-known 

 accuracy and carefulness of Dr. Mitchell, it might be supposed jiossibly that the 

 hypodermic syringe used in his experiments contained a certain amount of Croialua 

 or cobra venom, but under the circumstances such a hypothesis is entirely untena- 

 ble." The following year Dr. Mitchell still adhered to his original opinion, aad 

 undoubtedly does at the present time. 



Mr. Samuel Garman, of the Museum of Comparative Zoology of Harvard Univer- 

 sity, next made some very interesting experiments by allowing large and vigorous 

 Heloderms to bite the shaved legs of kittens, and here again these feline victims 

 refused to succumb to the effects of the wounds. , 



