THE RATTLE. 299 



Though no rattle is ordinarily developed until the snake- 

 ling is some months old, several cases are on record where 

 young snakes have been born with the ' button/ and even 

 with perfectly formed links. Mr. Benjamin Smith Barton, an 

 American who wrote a good deal about the Crotalus, 

 communicated to Prof. Zimmermann in 1800 that he had 

 found in a parent some young ones with three rattles, i.e. 

 * links,' each. Similar and more recent cases are on record. 



In colour a rattle is of a dark brown, or dull rusty black, 

 occasionally lighter when fresh and uninjured, 

 and then more plainly displaying its horny tex- 

 ture. In the Mexican rattle (p. 296) the links 

 were semi-transparent; sufficiently so to enable 

 us to trace the form of the interior links if held 

 against the light. This afforded an admirable 

 opportunity to comprehend the structure and 

 the production of the sound, which is simply 

 and truly a rattling of these loosely-fitting links 

 as they are partially embraced, each one by the Transparent ratiie (p. 



•^ -^ -^ '' 296), held against 



previous link. That is to say, each new link the light. 

 grows up into its predecessor, pushing it forward towards 

 the tip of the rattle. Through this unusually clear rattle you 

 can trace each link passing up and fitting into the preceding 

 (prior) one, just as so many thimbles or cups would fit into 

 each other. Only, in the case of thimbles or cups, there is 

 nothing to keep them in place, and the slightest shake would 

 detach the whole pile ; whereas the lobes or bulging sections 

 of each link prevent any such detachment in a rattle, 

 except by force or accident. 



The next is the rattle of a small Oregon snake. This, 



