THE ORDER OF SNAKES—OPHIDIA. 3 
the Ophidians, and which is only somewhat less developed in Blind Snakes 
and other Burrowing Serpents than in the typical forms. The two halves 
of the lower jaw in Ophidians are only united by an elastic ligament, and 
even the bony portions of the head are not firmly joined together, and, with 
the exception of the part protecting the brain, admit of a certain degree 
of expansion; by which means these snakes are enabled to extend their 
gape to an extraordinary degree, and swallow animals larger than themselves. 
Some kinds, such as the Australian Rock Snakes, are furnished 
with rudimentary hind limbs, in the form of small spur-like appendages 
near the vent, which, being absent from venomous species, serve as an 
indication that the reptiles which possess them are harmless. 
In a state of repose, serpents generally coil themselves up with their 
heads resting upon top of the coil. They are enabled to raise the body 
for a short time to about half its length without any support, but in a few 
seconds the raised part falls to the ground ; this may perhaps account for 
current stories about snakes springing at men and beasts. Those Australian 
Snakes which are allied to the Najas of India, such as the Black, Brown- 
banded, and Tiger Snakes, when irritated, remain for some time with their 
heads erect and moving backwards and forwards ready to strike, but no 
more than a third of their body is thus elevated. Nearly all snakes are good 
climbers, and with the least assistance, such as. the sides of a box, they 
can support the whole body, resting upon nothing but a part of the tail; 
even the short clumsy Death Adder is capable of performing this feat. 
The climbing power of the arboreal species—Tree Snakes and 
Rock Snakes—is truly wonderful. For instance, Tree Snakes which had 
been closely confined in an empty room, and could not be found for some 
time, were at last discovered upon the moulding of a door nine feet from 
the ground. 
Beyond a hissing and often peculiar drumming noise, snakes emit 
no sound. Neither the harmless nor venomous kinds will offer to bite 
unless they are hurt or driven into a corner whence escape is difficult, and 
if left alone they will scarcely stir. An instance is known of a person who 
picked up several stones close to a large Black Snake, without observing 
his danger till warned by the hissing sound peculiar to snakes when 
molested ; but no sooner had he proceeded to attack the reptile, by raising 
his foot to crush it, than it uncoiled and escaped. 
