238 
ANIMAL CURIOSITIES 
extend from the front to the hind limbs and 
are attached to the sides of the body. These 
act like a parachute and offer sufficient resist¬ 
ance to the air to prevent the animals from 
falling straight to the ground when they launch 
themselves from the branches of trees ; while 
the distance covered during their aerial journeys 
depends upon the height from which they 
commence their downward flight. 
In a way similar to the foregoing, the flying 
geckos also receive support from membranous 
flaps of skin ; while a certain snake from Borneo 
is said to be able to glide through the air by 
holding itself straight out and depressing the 
underpart of its body so that it presents a 
concave surface to the atmosphere as the 
reptile drops obliquely from a high elevation 
to a lower one. 
In the case of the flying-fish, however, it 
is not definitely proved whether their large 
wing-like fins act only as gliders, or whether 
they are employed for beating the air when 
the creatures are in flight, some writers being 
of the opinion that they hold their wings 
motionless when thus engaged, while others 
favour the alternative theory. 
Some of the spiders undertake aerial journeys 
by means of spinning long threads of such a 
fine texture that, wafted by the breeze, they 
