1900.] INSECTS OF THE " SKE AT 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 theplandon 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 cheeks 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 in a single group of insects, is proved, 

 if proof were necessary, by comparing the striped pupa from Aring 

 with the Arabian and African imago Idolum diabolicum 2 , a form of 

 which the natural colour and attitude have lately been described 



1 See Proc. Eoy. Phys. Soc. Edinburgh, Deo. 1900. 



2 P. Oambr. Phil. Soc. -vol. x. p. 175 et past., plate ii. 



Pkoc. Zool. Soc— 1900, No. LVI. 56 



