992 



THE NATURE BOOK 



defoliated rag- 

 wort ; and that 

 Sand Wasps, who 

 hax'e had their 

 paralysed prey 

 taken away from 

 them, will often 

 give themselves 

 the trouble of 

 finding a fresh 

 victim rather 

 than recapture 

 one which now 

 sho\\*s none of the 

 conventional 

 signs of resent- 

 ment, and must 

 therefore bs re- 

 garded as sick 

 and unfit for 

 Wasp consump- 

 tion. The field 

 naturalist, then, is 

 likely to acquire 

 the conviction 

 that, given har- 

 monious sur- 

 roundings, any 

 colour or combin- 

 ation of colours 

 may be protec- 

 tive, while, if the 

 surroundings are 



not harmonious, any colour or com- 

 bination of colours may be conspicuous ; 

 and he will account for the persistence 

 and comparative immunity of brightly 

 coloured insects which expose themselves 

 freely, by arguing that the immunity 

 may be closely connected with the 

 exposure itself, since insectivores generally 

 show marked preferences as to the kind 

 of food they wish to find and as to how 

 they wish to find it. It is noticeable in 

 this connection that the chief enemies 

 to wasp-like Flies are the Wasps them- 

 selves, who frequently take them on the 

 wing, but who seldom, as far as my own 

 experience goes, take them when settled 

 and at rest. 



Warning colours appear to afford but 

 little protection to such of our bright- 

 hued insects as survive the winter. The 

 queens of the social Bees and Wasps 

 select not only sheltered but concealed 

 situations to lie up in. The wings of our 



A TYPICAL BRITISH VAMiS'iA, THE PEACOCK 

 BUTTERFLY, WHOSE \C^INGS ARE WARNINGLY 

 COLOURED ON THE UPPER AND PROTECTIVELY 

 COLOURED ON THE UNDER SURFACE. 



hibernating But- 

 terflies are almost 

 without excep- 

 tion "warningly" 

 coloured on the 

 u p p c r surface, 

 and protectively 

 coloured on the 

 under surface. It 

 is the latter sur- 

 face only which 

 is exposed while 

 they are hiber- 

 nating. In most 

 Butterflies one 

 can trace on the 

 under surface of 

 each lower wing 

 a tendency for 

 the darkest por- 

 tion to be nearest 

 the insect's body, 

 and for the re- 

 mainder of the 

 wing to be broken 

 up with trans- 

 verse ribbon 

 markings across 

 the centre, and 

 chequerings o n 

 the outer border. 

 The result of this 

 arrangement i s 

 that with a suitable background the 

 external outline of the wing is lost 

 altogether. There is, in fact, an imper- 

 ceptible softening away of the wing from 

 the portion nearest the body outwards, 

 while the body itself, which in the normal 

 sleeping position is uppermost, is in most 

 cases in the shadow of the support to 

 which the insect is clinging. One can 

 hardly doubt that the exceptional colora- 

 tion of the under surface of the wings of 

 the Large Copper (there was a broad 

 warning orange band close to the outer 

 border and following its contour) may 

 have helped towards this handsome 

 insect's extinction. 



Though the theory of warning colours 

 cannot be said to have won universal 

 acceptance, it has nevertheless comjielled 

 universal attention, and mention must 

 be made of a variation of it, which is 

 due to Dr. Eisig. As the result of his 

 investigations in connection with a small 



