Explanation of Plates. 371 
with the head downwards than is shown in the plate. Perhaps the 
young larve under normal conditions invariably rest in this position. 
Figs. 1—13 represent the larve in the autumn of 1893, just before 
the beginning of hybernation. 
Figs. 14 and 15 represent the larvae, nearly mature in the last 
stage, in May 1894. 
Fia. 1. Larva of Gastropacha quercifolia just before hybernation, 
showing the effect of an environment of black-barked 
twigs (Quercus cerris). This typical example of the nine 
black larvae, chequered with white, described on Septem- 
ber 21st, 1893, was painted by Mr. Bayzand on September 
25th. Although these larvae had eaten very little, and 
had not grown appreciably by October 3rd, the white 
marks on six out of nine of them had become reduced 
almost to the condition represented in Fig. 3. The white 
patches on the larva shown in Fig. 1 had also become 
much duller and less conspicuous. The persistence of 
the process of colour-adjustment right up to the begin- 
ning of hybernation is very interesting, and contrasts 
remarkably with its entire cessation during and after 
hybernation. The difficulty with which the contour of 
the larvae could be made out against the black bark is 
correctly rendered in Figs. 1—3. 
2. Larva at the same period and exposed to the same environ- 
ment as that shown in Fig. 1. The figure represents the 
darkest larva, without any trace of white markings, 
described on September 21st. The painting was made 
on September 23rd. 
3. Larva at the same period and exposed to the same en- 
vironment as that shown in Fig. 1. This typical ex- 
ample of five out of the six darkest larvae, described on 
September 21st, was painted on September 26th. 
4. Larva just before hybernation, showing the effect of an 
environment of lichen-covered sticks. The lichen was 
probably Ramalina farinacea. The figure represents 
one of the four lightest coloured larvee produced 
in this environment and separated for painting on 
September 21st. The larva was painted on October 3rd. 
By October 16th, when the larve of series II were 
arranged for hybernation, many changes had taken place, 
but this larva remained among the lightest throughout. 
5, Larva at the same period and exposed to the same environ- 
ment as that shown in Fig. 4. The figure represents 
