The Descent of Man

Snakes produce other sounds besides hissing.
The deadly Echis carinata has on its sides some
oblique rows of scales of a peculiar structure
with serrated edges; and when this snake is
excited these scales are rubbed against each
other, which produces "a curious prolonged,
almost hissing sound." (63. Dr. Anderson, 'Proc.
Zoolog. Soc.' 1871, p. 196.) With respect to the
rattling of the rattle-snake, we have at last some
definite information: for Professor Aughey states
(64. The 'American Naturalist,' 1873, p. 85.),
that on two occasions, being himself unseen, he
watched from a little distance a rattle-snake
coiled up with head erect, which continued to
rattle at short intervals for half an hour: and at
last he saw another snake approach, and when
they met they paired. Hence he is satisfied that
one of the uses of the rattle is to bring the sexes
together. Unfortunately he did not ascertain
whether it was the male or the female which
remained stationary and called for the other.
But it by no means follows from the above fact