19-4 THE CANADIAN ENTOMOLOGIST 



such insects from their surroundings, although such discrimination 

 may be due in part to an abiHty to perceive form. By reason of 

 this apperceptional expectancy many insects also appear more 

 conspicuous amid certain surroundings than others. 



Table showing the effect of coloured backgrounds upon 

 insects, the colour nearest the name being that 

 against which it is most conspicuous, the follow- 

 ing colours being arranged in the order 

 approaching inconspicuousness : 



Colias philodice Gdt blue red green yellow 



Danais plexippus Linn yellow green blue red 



Pyrameis atalanta Linn yellow green blue red 



Plathypena scabra Fab yellow green red blue 



Mamestra trifolli Rott yellow red blue green 



Anasa tristis DeG yellow green red blue 



Murgantia histrionica Hahn . yellow green red blue 



Arilus cristatus Linn yellow green red blue 



Cyllene robinice Forst yellow green red blue 



Rhynchites bicolor Fab yellow green red blue 



Polistes variatus Cress yellow green red blue 



Eristalis tenax Linn yellow green red blue 



With most of the above species, at least, it is noticed that 

 yellow is more or less a fatal background, as far as inconspicuous- 

 ness is concerned. Green is less fatal, but it is only in the red 

 and blue that anything like protection is gained. 



The more the coloration of an insect approaches that of its 

 surroundings, the less conspicuous it becomes, but in all cases 

 apperceptional expectancy tends to make this, inconspicuousness 

 more complete, and, as a result, more protective. 



Dr. C. Gordon Hewitt, Dominion Entomologist, was elected a 

 Fallow of the Royal Society of Canada at the recent meeting. He 

 was also chosen to represent the Royal Society at the forthcom- 

 ing Jubilee of the Entomological Society of Ontario. 



During the months of June, July and August the editor will 

 be away from the city. Manuscripts for publication may be sent 

 to Mr. A. F. Winn, 32 Springfield Ave., Westmount, Que. 



