.336 Professor E. B. Poiiltou on colour-Tclation 



Two of the 6 caterpillars described above, including the 

 uniformly dark one, were selected for painting, together 

 with a representative of the 9 chequered larvae. The larva 

 without white markings was painted by Mr. Bayzand on 

 September 23rd, and is shown on Plate XVII, fig. 2 ; the 

 one with minute white markings on September 26th 

 (Plate XYII, fig. 3), and the chequered larva on September 

 25th (Plate XVII, fig. 1). 



II. G. qucrcifolia. 



By far the most marked result Avas seen in the 12 larvae 

 with an environment of lichen-covered sticks. Not one of 

 the 12 could be mistaken for any larva of the other 

 groups. In the case of 4 larvae the eliects were especially 

 marked, these being of a light colour over nearly the whole 

 of the exposed surface, the black ground-colour quite 

 rej^laced by a pale brownish tint in one and by grey in the 

 others. The 8 remaining larvae closely resembled each 

 other, being dark chequered with white ; but the ground- 

 colour, although dark, was not black like that of the larvjf 

 with Turkish oak (I), while the white markings possessed 

 a greyish tinge in one larva and a bluish in another. 



The 4 larva^ first mentioned were separated from the 

 others for painting at this date, together with the one in 

 which the markings were bluish-white, and another repre- 

 sentative of the commonest type of appearance, viz. a dark 

 ground-colour with white markings. 



III. G. qucrcifolia. 



The ground-colour of all the larva? with brown bramble- 

 stems was very dusky and brownish. Five of them had a 

 distinct brown patch on each side of the 2nd abdominal 

 segment, partially extending on to the 1st, and another 

 patch on the dorsal surface of the 5th abdominal. The 

 dorsal hum]) on the 8th abdominal, and in some larvae the 

 area surrounding its base, were also brown. In the remain- 

 ing larva? the light markings were more generally greyish 

 than white, and were often evanescent. Of the first-named 

 5 larva^ only one had the light markings well developed, and 

 this was selected for painting together with another in which 

 these markings were almost absent. The remaining larva? 

 were similarly represented by the larva with the white 

 markings best developed and the one in which they were 

 feeblest. 



