between lepidopterous larve and their surroundings. 313 
they afterwards came to resemble. This, however, is pro- 
bably not the case in the earliest stages, when the larve 
doubtless rest on the leaves and stalks. 
The extreme sensitiveness of this larva is clearly shown 
by a glance at Plate XVI. The four first figures indicate 
a power of adjustment about equal to that of the most 
sensitive larva hitherto known, Amphidasis betularia (com- 
pare Trans. Ent. Soc. Lond., 1892, Plate XIV). The effect 
of green leaves and shoots, shown in fig. 5, is however 
very inferior to that produced upon betwlaria, which 
becomes bright green in this environment. The effect of 
green leaves alone upon /identata is the same as that 
observed in many other larvae, Noctuz as well as Geometre, 
viz. the reduction of the brown ground-colour to a very 
pale tint which would be far less conspicuous than the 
more ordinary appearance. The contrast between the 
results of an effective environment of green, and nothing 
but green, as shown in fig. 5, and of green scattered over a 
brown background of bark, as shown in figs. 6 to 11, is very 
striking, and suggests renewed exper iments with an artificial 
arrangement of combined colours. Another interesting fact, 
suggesting the restriction of larval susceptibility to the 
immediate surface upon which the resting periods are 
passed, is the entire absence of any effects traceable to the 
green leaves of the food-plant when present with the 
other forms of environment employed in these experiments. 
The complex nature of the result produced is well seen in 
the oblique white lateral marks which are found in larve 
with the green lichen-like patches (figs. 6, 9), and probably 
assist in the general effect by breaking up the larval 
surface. The green markings are developed in the vicinity 
of and include the projecting ridges, etc.—a fact which 
is of obvious significance in promoting the resemblance 
to small scattered masses of lichen, The various kinds 
of lichen made use of did not produce corresponding 
effects.* Thus the green dorsal patches shown on the 
larvee which had been exposed to orange lichen (figs. 8, 
9) did not differ in any marked degree from those in 
which a green lichen had been chosen. It is by no means 
* My friend Professor S. H. Vines, F.R.S., has very kindly given 
me the probable names of the lichens made use of. They will be 
found in the detailed account of the experiments, and in the 
description of Plates XVI to XVIII. The names could not be given 
with certainty because the specimens themselves had been lost. 
