1900.] INSECTS OF THE “‘ SKEAT EXPEDITION.” 851 
mosses of the minutest size; so that large Locustids of yellows 
green, Pseudophyllus and others, which in the cabinet, and perhap- 
in their own place, form such admirable imitations of bamboo-leaves 
in colour, and to a lesser degree in form also (for doubtless they 
are part of the plancton of the jungle, and only gravitate down into 
its depths by misadventure), are the most conspicuous of the smaller 
jungle fauna which one meets with below. Yet all these shades 
are so altered and commingled in the chequer of deep shadow with 
occasional gleams of sunlight that they become completely confused 
to the eye. One is tempted to speculate as to whether the gorgeous 
tartan-like checks in which the Malays are so fond of clothing 
themselves may not have originally developed among a jungle-loving 
and somewhat murderous people at constant feud with their 
neighbours, as a means of secondary protective coloration, and 
have become more brilliant and less useful through the vagaries of 
sexual selection. On festive occasions these combinations of many 
colours are chiefly worn by the men, the women preferring for 
their holiday dresses simpler and more striking costumes into 
which only four or five masses of colour enter as a rule. On the 
jungle floor itself the most inconspicuous animals are certain long- 
legged but by no means bulky Phalangiids, which appear and dis- 
appear as they move or are still. Intrinsically they are of brilliant 
colours ; one species is black, speckled on the body and limbs with 
scarlet, white, yellow, and green. But they are less conspicuous 
even than the majority of Phasmids found in similar situations, 
even than the forms which have green markings resembling minute 
liverworts, such as cover the stems and leaves of the jungle flora, 
on their otherwise stick-like bodies; for it is generally easy to 
distinguish the exact outlines of such insects if they have once been 
located ; but even when the Phalangiids are moving it is rarely 
possible to see either their limbs or their bodies, though their 
motions are perfectly visible. Every such stick-insect resembles a 
particular stick, an ideal stick it is true; the Arachnids are assimi- 
lated, not to any particular object, but to their surroundings 
generally, by their irregular colour, their irregular form, and by 
the large extent of their surface in comparison with their bulk. 
The limbs of the Phasmids are often held in angular vegetable 
attitudes, but they do not always blend into their environment as 
the almost hair-like legs of the Phalangiids do; for it is often the 
case that the instinct of the insects is at fault in the choice of 
their immediate surroundings’, whereas the protective adaptation of 
the Arachnids, being general and not particular, does not necessitate 
any high specialization of instinct to accompany it. 
But that the object of brilliant coloration arranged in stripes 
is not always the same, even ina single group of insects, is proved, 
if proof were necessary, by comparing the striped pupa from Aring 
with the Arabian and African imago Jdolum diabolicum?, a form of 
which the natural colour and attitude have lately been described 
* See Proc. Roy. Phys. Soc. Edinburgh, Dee. 1900. 
* P. Cambr. Phil. Soc. vol. x. p. 175 e¢ post., plate il. 
Proc. Zoot. Soc.—1900, No. LVI. 56 
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