388 REPORT OF NATIONAL MUSEUM, 1893. 



ready for defense or offeDse. The rattle is then as a rule raised nearly 

 vertically in the middle of the coil, though it not only can, but really 

 does, rattle \yith the instrument poised outside of the body rings. When 

 shown the original drawing of the Banded Eattlesnake, now reproduced 

 on pi. 9, a friend of mine criticised the position as unnatural, since in 

 his opinion the snake could not sound the rattle outside of the coil. 

 Fortunately I had a huge live Texas Battler, CrotaJvs atrox, near by, 

 and upon repairing to the cage and trying to induce the monster to 

 rattle, his very first performance was g'iven in the i^osition shown in the 

 criticised illustration. 



The rattling- sound is ])roduced by a vigorous shaking and vibrating 

 of the end of the tail, the dead, horny cones i)roducing a noise of dif- 

 ferent pitch and volume dependent upon the size and vigor of the ani- 

 mal and the dryness of tlie rattle. Under ordinary circumstances the 

 sound is not kept up constantly for any length of time, but that is not 

 for want of ability, for it is well known that captive Rattlesnakes may 

 be induced to rattle continuously for hours. 



Dr. Feoktistow, in the memoir already quoted, has given an account 

 of an interesting experiment made for the purpose of ascertaining the 

 number of vibrations which the rattle makes i^er minute, which deserves 

 to be reproduced here : 



A large Rattlesnake was grasped by the neck, while an assistant thrust a needle 

 through the middle joint of its seven-jointed rattle in such a way that it pierced 

 the rattle in its greatest diameter, consequently from above downward, if we imag- 

 ine the snake lying quiet with its tail outstretched upon the ground. Now, since 

 the rattle (in the position in which we have supposed the snake to be) is, in making 

 a noise, moved from left to right and back again, the needle was able to trace curves 

 of vibration upon paper blackened with soot. As a registering apparatus I used 

 Dudger-n's polygraph, with a strip of blackened paper which Avas made to slide rap- 

 idly forward by means of the clockwork. The tail of the snake was, to a certain 

 extent, fixed by my holding the snake with my hand in the region in front of the 

 vent. After much trouble I succeeded in bringing the needle in a suitable manner 

 into contact with the strip of paper, and in obtaining curves of vibration, from 

 which the number of the vibrations per minute (the rajtidity of the progression of 

 the strip of paper being known) could be calculated witli a fair degree of accuracy. 

 In this manner it was found that the movements of the rattle are composed of gi'eat 

 vibrations of the entire tail itself and of smaller vibrations of the actual rattle in 

 such a way that the tail makes 75 and the rattle, on the other hand, 110 vibrations 

 per minute. These are approximate average numbers, since I was able to obtain 

 only faulty curves, because the rattle does not perform its vibrations precisely in one 

 plane. Movements kept up for hours with rapidity like this are absolutely amazing. 

 When observed with the naked eye, only a blurred image is seen of the rattle mov- 

 ing at this rate. 



The Russian investigator was not the first, however, to attempt a 

 determination of the vibrations of the Rattlesnake's tail. Dr. Isaac 

 Ott, as early as 1882, tried an exj)eriment similar to that of Dr. Feok- 

 tistow. From his statement* it may be sufficient to quote the fol- 

 lowing : 



* The Vibration of the Rattlesnake's Tail. Journ. Nerv. and Mental Disease, 

 New York (n. s.), vii, Jan. -Oct., 1882, pp. 514-516. 



