Butterflies and Moths, 407 
observation was made. The Cambridge Natural History says that 
butterflies of the genus Ageronia delight in settling on the trunks of 
trees rather than on flowers and leaves, and make a clicking noise with 
their wings, both when in flight and at rest. ‘lhe object of the noise 
is quite uncertain, but it is suggested that it is done in rivalry or 
courtship, or to frighten away enemies. It has been observed, however, 
in South Brazil that the Sound attracts a lazy little bird which sw oops 
down and eats the clicker. The mode in which the sound is produced is 
not quite clear, but Sir George Hampson has pointed out that the fore- 
wings have at the extreme base a small appendage bearing two hooks, 
and that two other processes on the thorax play on these w vhen the w ing 
moves. His suggestion that these hooks are the cause of the sound 
seems highly probable. 
Butterflies alight or rest with their wings expanded horizontally, or 
closed perpendicularly over the back, the latter being the more usual 
habit. Both ways of holding the wings may frequently “be seen in some 
species, for example, in Anar ria jatrophe, our common inarbled butterfly, 
while others habitually adopt either the one way or the other. The 
gorgeous blue Morpho, that wins the admiration of every traveller in 
our hinterland, and is the desideratum of many an insect collector, rests 
with wings closed and elevated perpendicularly over its back, so that 
their comparatively dull under-surface is exposed to view. This habit 
gives the insect the power of vanishing from sight most mysteriously. 
We see it, as it flies along, as a dazzling blue object that captivates 
the eye, and of a suck len it disappears. We advance to the spot 
where it vanished, and though we know it must be at rest on some twig 
or tree-trunk right before us, a careful scanning of our surroundings 
may fail to bring it into view. Indeed, the first indication we may 
have of its presence may be as we unintentionally startle it from a 
point scarcely a yard from us, and it resumes its flight as a conspicuous 
blue object. The Morphos belong to one of the subdivisions of the 
extensive family of Nymphalide, which, as a rule, keep their wings closed 
and elevated when at rest. Gynaciu dirce may be mentioned as another 
excellent example of a spectral or hide-and-seek butterfly. Junonia 
cenia, too, has the power of performing the vanishing trick, but in a 
different manner. If hotly pursued, it just drops plump down into tall 
grass or tangled bush. and no amount of searching will then tind it, even 
though we feel certain we are rummaging the exact spot where we saw it 
descend. Twice this butterfly tricked me so, once near Kitty, and again 
on the Coomacca savannah. 
The Lycenide, which may be called our “ blues,” also rest with the 
wings closed and elevated, so that the rich blue, which in most adorns 
the upper surface of the wings, flickers into sight only when the insects 
are on the wing. When at rest they often gently slide the wings up and 
down alternately, so that the delicate tails of the hind-wings keep up a 
vibration. 
