( xlvi ) 



considerable amount of zebra-like colouring among the Longi- 

 corns and perhaps certain Rhynchophora : the black and white 

 stripes may be arranged longitudinally as in Ornithia, Platy- 

 arthron, Txniotes and many species of JDorcadion, or horizon- 

 tally or in more or less confluent rows of spots as in Tmesisternus, 

 Stenygra, Colobothea and others. In the present state of our 

 knowledge we cannot draw the line between protective resem- 

 blance and warning coloration in these cases ; even a conspicuous 

 species like Belt's Jjongicom Deliathis nivea may be, and probably 

 is, well protected by its surroundings. One of the best instances 

 of obvious protective resemblance among the Coleoptera, how- 

 ever, appears to be found in the large and handsome Longicorn 

 Petrognathus yigas from India : not only does its upper surface 

 closely resemble dead velvety moss, but its antennae are exactly 

 like dry wood tendrils : Xylorrhiza venosa is almost as striking 

 an example : this portion of our subject is almost inexhaustible, 

 but we cannot pursue it further. 



With regard to cryptic forms we need only mention the 

 resemblance of certain beetles to seeds, knobs of bark, bunches 

 of lichen, etc. : there are many instances of these and some 

 have before been alluded to : the occurrence of protective forms 

 is much more prevalent among the Homoptera : the members of 

 the large genus Umbonia, for instance, so closely resemble the 

 thorns of the plants on the stems on which they sit that it is 

 impossible to distinguish them without close examination. 



3. There is no time to say much upon the subject of 

 warning colours, but we shall speak of them again under 

 the heading of Mullerian Mimicry : we find them well pro- 

 nounced in the case of the Coccinellidae and Telephoridre which 

 are known to be distasteful : it has even been suggested that 

 the light of the glowworm is to a certain extent warning, but 

 there seems to be no confirmation of this: we may however 

 say broadly that, when we see an insect coloured in strong 

 contrast to its natural surroundings, it is either distasteful 

 or a mimic of a distasteful species. 



4. Under cryptic attitudes we may include the curious 

 method in which certain Staphylinida?. contort their bodies 

 into a small space and remain motionless, and also the habit 

 of simply drawing in their legs and suddenly dropping and 



