Mimicry 



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as follows : u Take two inches of dried yellow grass stalk, 

 such as one might pluck to run through the stem of 

 a pipe ; then take six other pieces nearly as long and 

 a quarter as thick ; bend each in the middle at any angle 

 you like, stick them in three opposite pairs, and again at 

 any angle you like, upon the first grass stalk and you 

 have my * Chirombo ' [native name for the stick insect]. 

 When you catch him, his limbs are twisted at every angle, 

 as if the whole were made of one long stalk of delicate 

 grass, hinged in a dozen places, and then gently crushed 

 into a dishevelled heap. Having once assumed a position, 

 by a wonderful instinct he never moves or varies one of 

 his many angles by half a degree. The way the insect 

 keeps up the delusion is indeed almost as wonderful as 

 the mimicry itself, and you may turn him about and over 

 and over, but he is mere dried grass, and nothing will 

 induce him to acknowledge the animal kingdom by the 

 faintest suspicion of spontaneous movement." 



The stick insects have their counterpart in this country. 

 Everyone knows some, at least, of the large family of 

 "looper" caterpillars, the insects which derive their name 

 from their curious looping gait, rendered necessary by the 

 fact that they have legs at either end of their bodies and 

 none in the middle. There are many species, but all have 

 the same habit, which renders them difficult to detect when 

 at rest. Feeding, for the most part, by night, when they 

 are safe from the attacks of birds, they rest motionless by- 

 day. Taking a firm hold on some twig of their food plant 

 with their hind legs, they attach a fine thread of silk to 

 their support and posture themselves in an erect position, 

 thus bearing a striking resemblance to a broken twig of 

 the plant on which they are resting. 



Brown caterpillars select brown twigs, green ones 

 favour green twigs, and, in either event, are very difficult 

 to detect. The silken thread acts as a stay-rope and 

 takes a considerable amount of the strain which the insect 

 would otherwise feel in its immobile periods. 



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