VARIABLE PROTECT] VE RESEMBLANCE IN INSECTS 131 



mination of the upper and lower colours. The bottom 

 of a shallow wooden box was covered with alternate 

 areas of black and gilt paper, and partitions were 

 fixed along the lines where the two colours came into 

 contact. Each par- 

 tition was gilt to- 

 wards the gilt surface 

 and black towards 

 the black, and was 

 perforated close to 

 the bottom of the 

 box with holes which 

 would just admit the 

 body of a larva. The 

 box was then placed 

 in a vertical position 

 towards a strong 

 light, so that the 

 partitions became 



horizontal shelves, while the black and the gilt sur- 

 faces were uppermost alternately. As soon as a larva 

 was suspended to a glass sheet, the boss of silk was 

 carefully scraped off and was pinned on the upper colour 

 above one of the holes, so that the head and first five 

 body-rings passed through the hole on to the colour 

 beneath, which tended to produce opposite effects. 

 Other larvae were similarly fixed between the shelves 

 upon one colour only, so as to afford a comparison 

 with the results of the conflicting colours. 



Fig. 30.— The larva of Small Tortoiseshell Butter- 

 fly suspended in a tube of which the upper 

 compartment is lined with gilt, the lower with 

 black ; X 2. s. Boss of silk. b. Black, c. Card- 

 board, g. Gilt. 



