CROTALUS DUR1SSUS. 59 



first formed cup of the rattle is connected directly with the scales 

 on the back, and, by the intervention of a row of small scales, with 

 the shields on the belly. Each cup consists of two quadrangular 

 pyramids, which are joined together by their points and flattened 

 laterally ; that nearest the tail is much the largest, hollow within 

 and convex externally, whilst that which is towards the tip is 

 nearly flat, and receives upon it the hollow pyramid of the next 

 ring, the base of the former making a projection, over which the 

 second ring cannot slip ; in this mode the larger pyramid, which 

 is somewhat of an oval shape, with its long axis from above down- 

 wards, is seen, except at the tip of the rattle where both are visible, 

 and shew the formation of each ring, and the shape of the last 

 caudal vertebra, upon which each is formed as upon a mould. 

 The number of cups found in a rattle depend upon the age of the 

 snake, and these are said sometimes to amount to twenty or thirty ; 

 their usual number, however, is from five to fourteen. When the 

 reptile moves its body, the cups of the rattle likewise moving upon 

 one another, make a noise, which has been compared, though not 

 very correctly, to the folding of dried parchment. This noise is 

 distinctly audible at the distance of twenty or thirty feet, but as 

 the cups consist merely of dried matter, which in the dry season is 

 brought into a condition to make a noise when the animal moves, 

 so in like manner, under the influence of external circumstances, 

 the rattle in the wet season is soft and mute. 



The Rattle-snakes are slow inactive creatures, and seldom attack 

 a man unless molested ; but this is often done unguardedly by 

 treading on their haunts. They usually rest twisted in a spiral 

 form, in places which are clear of grass and wood, where they lay 

 wait for such ill-fated animals as chance to prowl within their reach. 

 Their bite is almost uniformly fatal, even to the largest animals ; 

 and the latter frequently evince such an instinctive dread of them, 

 that, according to M. Bosc, it is almost impossible to compel a 

 horse or dog to advance towards them. Their food consists prin- 

 cipally of the smaller quadrupeds, such as squirrels, rabbits, rats, 

 hares, and small birds. It was long believed, and the notion is 

 still popularly current in America, that they possessed the power 

 of charming, as it is commonly called, or fascinating their victims, 



