336 Professor E. B. Poulton on colowr-relation 
Two of the 6 caterpillars described above, including the 
uniformly dark one, were selected for painting, together 
with a representative of the 9 chequered larvee. 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 XVII, fig. 3), and the chequered larva on September 
25th (Plate XVII, fig. 1). 
Il. G. quercifolia. 
By far the most marked result was seen in the 12 larvie 
with an environment of lichen-covered sticks. Not one of 
the 12 could be mistaken for any larva of the other 
eroups. In the case of 4 larvee the effects were especially 
marked, these being of a light colour over nearly the whole 
of the exposed surface, the black ground-colour quite 
replaced by a pale brownish tint in one and by grey in the 
others. The 8 rem: uining larve closely resembled each 
other, being dark chequered with white; but the ground- 
colour, although dark, was not black like that of the larvee 
with Turkish oak (1), while the white markings possessed 
a greyish tinge in one larva and a bluish in another. 
‘The 4 larve first mentioned were separated from the 
others for painting at this date, together with the one m 
which the markings were bluish- white, and another repre- 
sentative of the commonest type of appearance, viz. a dark 
eround-colour with white markings. 
iG: quererpolra, 
The ground-colour of all the larvee 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 Ist, and another 
patch on the dorsal surface of the 5th abdominal. The 
dorsal hump on the 8th abdominal, and in some larvae the 
area surrounding its base, were also brown. In the remain- 
ing larvee the light markings were more generally greyish 
than white, and were often evanescent. Of the first-named 
5 larvee 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 larvee 
were similarly represented by the larva with the white 
markings best dev eloped and ‘the one in which they were 
feeblest, 
