Proceedings of the South African Philosophical Society. Xxxil 
absorption or disappearance of these organs will be compensated by 
an increase in size of other organs useful for protective purposes, 
such as a still better adaptation to the squatting habit by the 
development of broader femora, &c. 
This is well proved in the case of Methone, the most perfectly 
protected of all these insects. It is wingless and has only a rudimen- 
tary wing-cover in both sexes. The enormous development of the 
thighs (femora), which are held, when the insect squats, against the 
side of the abdomen, certainly helps considerably to bring the shape 
of the body into harmony with the relief or contour of the ground. 
In the Neuroptera, all of which are carnivorous, I know of 
only one possible case of adaptive colouring, the myrmeleonidous. 
Glenurus excentrus, in which the position of the wings when the 
insect is at rest, enhances the protection obtained by their colour- 
ation. This manner of carrying the wings when in repose differs. 
from that of the other Myrmeleonide. 
In the HemrpreRA-Homoptera, to which Order belong the Bugs, 
Cicadze, and Scale-Insects, protective colouring seems to be restricted 
among the Pentatonide to the ubiquitous green Nezara and Cyclo- 
gaster (N. capensis, N. pallido-conspersa, C. pallidus, &c.), which are 
found on green plants, and to the mottled Cenomorpha nervosa and 
Atelocera stictica, found here on the oak-tree, but in most instances 
the markings, often very brilliant and highly conspicuous, are of the 
warning sort. Most of them dispense a most pungent and generally 
offensive smell, which is notorious. 
Nothing can be more like the bark of the trees to which they cling 
than the mottled South African Cicad@ (Singertjies). It would seem 
easy for any one to locate our common species, Platyplewra striata,, 
for its ear-plercing noise guides one easily enough to the trunk of 
the willow-tree on which it rests ; but when one draws near, its music 
ceases, and then it is well-nigh impossible to perceive the insect. 
Three species of this genus, which are not inhabitants of our neighbour- 
hood, display a greenish colour on the surface, and in one, P. divisa, 
the upper side is clothed with fine, silky hairs conspicuously imitating 
fine moss or minute lichens. Pyrops tenebrosus imitates a stump of 
wood. On the other hand, the brightly coloured Hddasa euchroma,. 
filinorta guttata, Ptyelus grossus, do not seem to imitate anything, 
and yet they are almost entirely invisible on the tree-trunks where 
they stand. They are surrounded by a broad patch consisting of a 
white, somewhat flocculent substance exuded by themselves. So: 
much lost are they on that white surface that during a journey to 
the Transkei I found great difficulty at first in detecting these insects. 
I suspect that we have here a case of indirect protective resemblance. 
