1[8 Kusnezov, Die Bedeutung der Färbung der Hinterflügel der Catbcala-Artea. 



which the insect alights than there would be if such colour had 

 never be displayed. In California 1 noticed a very similar instance 

 in one of the Arctiadae (or Catocalidae), which had precisely similar 

 habits. It frequented the dry stones in the bed of a river left by 

 the shrinking of the water to its suramer liraits. It had orange 

 hind wings with black bars or mottlings, which were very con- 

 spicuous during its short flights, but on alighting it became almost 

 absolutely invisible; the fore wings being coloured exactly as the 

 stones among which it dropped, and from which it was not easily 

 disturbed. — In our own country we have conspicuous instances 

 in the genera Catocala, Triphaena, Heliodes, and others. Who has not 

 noticed the deceiptive effect of the bright yellow under wings dis- 

 played in the short flights of Triphaena pronuba, and the -extreme 

 difficulty of following its movements at the moment when these 

 are no longer visible, as it darts down among the grass-roots, 

 where it is offen extremely difficult to detect or to dislodge? If 

 this protective effect of the partial and intermittent display of 

 brilliant colouring is so obvious in relation to the human eye, must 

 it not be at least equally so in relation to the eyes of its more 

 natural enemies, such as birds, and have we not here indicated a 

 new and distinct line of investigation as regard the use and advantage 

 of brilliant colours in many cases which cannot be accounted for 

 by the theory that they are developed for the purpose of warning, 

 or through their aestetic relation to courtship? Mr. Poulton has 

 attempted to account for some of these appearances by the idea 

 that birds in pursuit of insects would strike with their beaks at 

 the most conspicuous part, and that the body or more vital part 

 would be thus protected at the expense of a few chips out of the 

 hind wings; but in some instances, especially in exotic Arctiadae, 

 the body itself is the more conspicuous and ornamented part of 

 the insect. For such cases this theory, however partially true it 

 may be, would fail to account; moreover, it can scarcely be denied 

 that the insect, if less conspicuous in its flight, would be less likely 

 to attract the attention of -the bird, and therefore less liable to 

 attack." 



Dieser Hypothese Lord Walsingham's schloss sich auch 

 Hudson im Jahre 1898 vollkommen an; in der Einleitung zu seiner 

 Arbeit „New Zealand Moths and Butterflies" schreibt er auf S. XV 1 ): 

 „Contrast colours. — In this class of colouring the fore wings 

 only are protectively coloured, the hind wings being very conspi- 

 cuous. Contrast-colouring is well exemplified by several of the 

 insects included in the genus Notoreas. The sudden exhibition of 



1) Hudson, G. V. New Zealand Moths and Butterflics (Macrolepidoptera) 

 London, 1898, in 4". 



