BREATHING AND HISSING OF SNAKES. 157 



may not another do the same ? — an argument which I 

 venture to use notwithstanding many herpetologists accept 

 doubtfully the possibility of a snake producing such a 

 sound. * II est difficile a concevoir comment les serpents 

 auraient la faculte de siffler, comme on pretend que peuvent 

 le faire certaines esp^ces de couleuvres, et comme les poetes 

 se plaiscnt a nous les representer. Jamais nous n'avons pu 

 entendre qu'un soufflement tres sourd, provenant de I'air 

 qui sortait avec plus ou moins de rapidite de I'interieur de 

 leur poumon que Ton voyait s'affaisser en trouvant une 

 issue par la glotte, a travers les trous des narines ou 

 directement par la bouche dont la machoirc superieure est 

 naturellement echanchrde. Alors la bruit ctait seulement 

 comparable a celui qui resulterait du passage rapide et 

 continue de I'air dans un tube ou par un tuyau sec et 

 etroit, comme serait celui d'une plume.' ^ 



This no doubt answers to the ordinary ' hissing ' of the 

 majority of snakes ; but that the sound varies under certain 

 conditions, and in the same serpent, cannot be denied. 

 A. R. Wallace relates an incident which may well be 

 introduced here, as affording both a proof of the length 

 of time snakes can sustain a sort of half suffocation, and 

 also the expression or power of ' voice ' in breathing. A 

 young boa was caught, and in order to prevent its escape, 

 its captors, while preparing a box in which to convey 

 it away, tied it tightly round the neck to a thick stick, 

 which not only fettered its movements, but appeared to 

 early stop its respiration. It lay writhing in much dis- 

 comfort, sometimes opening its mouth with a suspicious 



' Dumeril ct 13ibron's Erp'-tologie gciitralc, tome vi. p. 186. 



