208 ROMANCE OF THE INSECT WORLD CHAP. 



gray, the disposition of the two colours being sym- 

 metrical and in endless variety of design. Nearer 

 home, to take a familiar example, the large and com- 

 mon caterpillar of the Privet Hawk Moth {Sphinx 

 ligustri) is in reality striking in its green dress and 

 purple stripes. But although it looks so conspicuous 

 it harmonises remarkably well with its food-plant, 

 and is sometimes troublesome to find. The purple, 

 a dangerous introduction of colour one might be led 

 to suppose, tends to neutralise the vivid effect of the 

 extensive green area. 



However, deception of assailants or assistance in 

 capture is often obtained by the reproduction with 

 great exactness of the colour of the soil, or the 

 vegetation inhabited by the insects. Of this mode 

 of defence the beetle family offers no dearth of illus- 

 tration. Among Cicindela, C. campestris frequents 

 grassy slopes and is green ; C. maritima is found 

 only on sandy shores by the sea, and is of a pale 

 brownish yellow. Dr. Wallace discovered many of 

 these insects in the Malay Isles invariably in 

 harmony with their place of abode. C. gloriosa, of a 

 velvety- green, was always taken on wet mossy stones 

 in the bed of some mountain stream, the brown 

 C. heros chiefly on dead leaves in the forest paths. 

 The wet mud of salt marshes alone furnished a 

 glossy-olive species, so closely corresponding to the 

 colour of the mud that it was only distinguished, when 

 the sun shone, by its shadow ! Where the beach was 

 coralline and nearly white, Wallace saw a pale 

 Cicindela ; where it became volcanic and black, a 

 dark species of the same genus presented itself. A 



