1889 .] 
176 
LGarman. 
it may always be recognized by its simple rounded outlines and lack 
of some of the constrictions and shoulders. Even when the rings 
are all present they cannot be said to give a certain indication of 
the age of the individual. Apparently each slough adds one ring ; 
the number of sloughs may vary from one to several in a season. 
From the first ring to about the seventh, in the larger species, and 
to about the sixth in the smaller ones, the increase in the size of the 
body is usually very rapid ; this is traced in the comparative sizes 
of the rings. Each succeeding being larger than the predecessor, 
the series is of the acuminate or tapering pattern. After the seventh 
or eighth the sizqs are more nearly the same, and thenceforth the 
rattle is of the type formerly described as parallelogrammic. Rings 
being acquired in the spring as also in the fall, the age of a speci- 
men in possession of a complete series may better be estimated by 
counting two rings to the year. The shape of the hindmost ring 
will decide any question as to presence of all the rings. On large 
individuals an entire series is rarely found. 
On the uses of the rattle there is not a great deal to be said. Very 
thick- tailed species and, possibly, those with prehensile tails being 
excepted, snakes pretty generally are addicted to making a rat- 
tling noise, when excited, by striking the tail from side to side. 
Primarily these motions may have indicated only nervous excite- 
ment ; meaning no more than the movements of the tail of the cat ; 
or they may have originated in efforts to prevent attacks upon the 
sensitive organ by various enemies, from insects to carnivores, the 
dangers besetting serpents being similar to those met with by so 
many of the lizards. Whether the movement and rattling as de- 
veloped in later times have come to signify more is still a subject of 
inquiry. Possibly the motions and sounds of the tail may in at- 
tempts to capture prey serve to distract the attention of the vic- 
tim from the head, that the spring and seizure may be more suc- 
cessful. At any rate, when a rattlesnake is excited, he springs 
his rattle. When anxious to escape observation he makes no 
sound. On such occasions he will pass very near a person, going 
on his way in silence. Should accident betray him, and should 
he realize the fact, from a quick motion or even a passing shadow, 
lie at once throws himself on the defensive and sounds a warning 
against any offender. By preventing cattle, horses and other animals 
from treading upon him the rattling certainly would prove benefi- 
cial. It is likely that, beyond this, the greater benefits are derived 
