196 THE COLOURATION OF INSECTS 



sematic groups. Cryptic colours are divided by Poulton 

 into Procryptic and Anticryptic. Procryptic colouring 

 conceals its wearer from danger, causing it to resemble 

 either the general surroundings or some particular part 

 thereof (Special Procrypsis), Instances of the former, 

 such as a green grasshopper among grass, or a mottled 

 grey-brown weevil on earth, are so numerous and well 

 known that no further examples need be mentioned. 



Special procryptic colouring never fails to arouse 

 wonder from its extreme perfection ; indeed, it has been 

 said that these resemblances are so minutely perfect that 

 Natural Selection cannot possibly have produced them. 



This complimentary doctrine has been termed Hypertely. 



Even in the British Isles stick-like caterpillars abound, 

 which are quite indistinguishable until they move. Here 

 one must urge a point which is often overlooked. Natural 

 Selection, in producing special procrypsis, has not only 

 altered the shape and colour of the insect, but has pro- 

 duced deeply seated changes in the neuro-muscular system. 

 A stick-like caterpillar needs to maintain itself motionless 

 for hours in an attitude very unusual for the majority 

 of caterpillars, and one which must require great develop- 

 men of muscle for that special purpose. 



As an example of another attitude, very unusual, but 

 associated with an especial scheme of colouring, the 

 following is of interest. 



In 1910 I found at Jinja, on the north shore of Lake 

 Victoria, a moth,^ allied to our English Lucania, among 

 some very dry dependent spikes of grass flowers, of a 

 light silvery grey tint. The moth was hanging in an 

 inverted position with wings brought together over the 

 back ; their under surfaces thus exposed were of a silvery 

 grey hue closely corresponding with that of the dried 

 glumes of grass. But this colour was only shown on those 

 surfaces that were visible ; the part of the fore wing 



' A species of Cirphis. 



