688 EEPTILIA. 



process of the temporal muscle (d), which is attached to a thin apo- 

 neurotic line (e). The greater portion of the fibres of this muscle take 

 their origin from the capsule of the secreting apparatus, which they 

 partially envelope ; and then winding round all the posterior part of the 

 gland, and passing behind the commissure of the lips, the lower part of 

 the muscle is firmly implanted into the lower jaw very far anterior to 

 the angle of the mouth. The process of the temporal muscle which thus 

 surrounds the gland is very thick and strong, so that it is easy to imagine 

 with what force the poison will by this mechanism be injected into the 

 wounds inflicted by the fangs, seeing that the same muscles which close 

 the jaw at the same time compress the bag of venom with proportionate 

 energy. 



(1921.) Behind the large poison-fang in use, the capsule that en- 

 closes it generally contains the germs of several others, ready to supply 

 its place should the former be broken off ; and in the event of such an 

 accident, one of these supplementary teeth soon becomes consolidated 

 with the superior maxilla, and adapted in all respects to take upon 

 itself the terrible office of its predecessor. 



(1922.) Dreadful as are the means of offence thus conferred upon the 

 poisonous serpents, it is impossible to avoid noticing in this place that 

 admirable provision of Nature which, in one genus at least, serves to 

 give timely warning of the vicinity of such dangerous assailants. We 

 need merely mention the rattle of the Rattlesnakes (Crotalus) an 

 organ the intention of which is so obvious that the most obtuse cannot 

 contemplate it without at once appreciating the beauty of the con- 

 trivance. This singular rattle is formed of numerous horny rings, that 

 are in fact merely modifications of the general scaly covering of the 

 reptile, so loosely articulated together that the slightest movement of 

 their formidable possessor is betrayed by the startling noise produced 

 by the collision of the different pieces composing the organ : even when 

 at rest, the creature announces by rapid vibrations of the tail the place 

 of its concealment, apparently to caution the inadvertent intruder 

 against too near an approach. 



(1923.) In the grand police of Nature, the scavengers are by no 

 means the least important agents. In hot climates especially, where 

 putrefaction advances with so much rapidity, were there not efficient 

 and active officers continually employed in speedily removing all dead 

 carcases and carrion, the air would be perpetually contaminated with 

 pestilential effluvia, and entire regions rendered unhabitable by the 

 accumulation of putrefying flesh. Perhaps, however, no localities could 

 be pointed out more obnoxious to such a frightful cause of pestilence 

 than the banks of the tropical rivers those gigantic streams which, 

 pouring their waters from realm to realm, daily roll down towards the 

 sea the bloated remains of thousands of creatures which taint the atmo- 

 sphere by their decomposition. 



