10S 
PROCEEDINGS OF THE PERTHSHIRE SOCIETY OF NATURAL SCIENCE. 
panied by the ejection of a fluid which, on contact with 
the air, immediately volatizes, and appears like a puff of 
smoke, from which they derive their military title. 
In coming to the Lepidopterous order, or the butterflies 
and moths, I shall consider them rather more minutely than , 
I have done the other orders. On looking at some of our j 
common butterflies, one might suppose at first sight that ; 
they would be exposed to great danger on account of 
their very gay and conspicuous colours ; but I shal^ ; 
endeavour to shew, and I trust to your satisfaction, | 
that such is not the case. We must remember that 
the time of danger to these beautiful insects is not so 
much when they are engaged in flight as when they are at | 
repose. Now, from the position they assume when at rest, 
— which is with their wings erect, haviug the upper sur¬ 
faces folded together,—they expose only the under sur¬ 
faces of their wings. The Admiral (Vanessa Atalanta), 
the Peacock fV. Io ), the Tortoiseshell f V. UrticceJ, and the 
Blues, are allgood examplesof this. The littleandbrightly- 
coloured copper (Polyommatus Phlccas) is so similar when 
at rest to the withered ferns and grass on which it delights 
to rest, that it is almost impossible to see it. The Gray¬ 
ling (Satyrus semele) defies detection by the similarity of 
the colouring of the under-side to the face of the rock on 
which it rests; and although you can see one fly to a cer¬ 
tain spot, it is very difficult to find it until it again takes 
wing. The Green Hairstreak ( Thecla rubi) is another 
which as soon as it settles on anything green is entirely lost 
to sight. These cases, I think, clearly indicate the uses of 
the sombre and mimetic appearances of the under-sides of 
the wings. 
Turning our attention now to the moths, we shall 
find the same remarks as to the bright colouring to hold 
good here also, namely, that when at rest the bright¬ 
ness is usually hidden from view, but we find a material 
difference in the part where it is located owing to the 
different position of the wings when at rest. Most moths 
do not keep their wings up like the butterflies, but fold them 
flat over their bodies,—the fore wings overlapping and hid¬ 
ing the hind wings, so that only the upper surfaces of the 
front wings are exposed to view. On examining these 
moths we shall find that almost all that have bright colours 
have them placed on the hind wings, and the front wings 
are usually of dull or quiet tints. You will see this in the 
Eyed Hawk [Smerinthus ocellatus), the Tigers ( Callimorpha 
dominula, Chelonia caja, and C. villica), the Red and Yellow 
Under wings, &c. The Rev. Joseph Greene has pointed 
out the striking harmony that exists between the colours 
of the British moths on the wing during autumn and 
winter and the prevailing tints of Nature at those seasons. 
In autumn various shades of yellow and brown prevail, and 
he states that out of 52 species that fly at that season no 
less than 42 are of corresponding colours. In winter, grey 
and silvery tints prevail, and the moths, at this season, 
are of harmonious hues; and no doubt from this genera 
harmony with the aspect of Nature at the times when they 
respectively appear these moths receive many advantages. 
Stones, stone walls, and the trunks of trees—-especially 
those covered with lichens—are favourite resorts for many 
moths to rest upon, and these moths are often so similar in 
their colouration to their surroundings that detection is 
very difficult. Such, for example, as Bi'yophila perla _ 
Acronycla psi, Larentia ccesiata, Boarmia repandata , and 
many of the geometric. The Buff Tip (Pygcera bucephala), 
from its position and the markings of its wings, 
looks just like a broken lichen - covered branch. 
The Lappet Moth ( Basiocampa Quercifolia), too, might 
easily be mistaken for a bundle of withered leaves. One 
family of moths seems to have discarded the scaly wings 
peculiar to their order, and to have assumed clear wings, 
resembling bees, hornets, ichneumons, &e., and seems to 
receive immunity of attack from imitating their stinging 
neighbours. Among moths, too, there are many species 
in which the female is wingless, or at all events the wings 
are in a very rudimentary condition.—whether through 
disuse or not, it does not concern us now,—but I think 
they thereby receive advantages which they could not 
possibly have were they winged like their partners. 
As most of them are what I may call winter 
visitors, I think their wingless condition is evidently one 
of protection. The moth Winter Beauty ( Phigalia Pilo- 
saria) emerges from the pupa state about January. The 
male being of a silvery tint, and similar to the trees on 
which it is found, receives good protection from its colours; 
—the female, however, being wingless, is much more pro¬ 
tected, and is very rarely to be met with in Nature, as it 
can get between the crevices of the bark, and so be entirely 
out of sight. These remarks also apply to other wingless 
moths, such as Cheimatobia brumata,Hiibernia ri-jncapraria, 
H. Proqemmaria, &c. In the pupa state, too, moths need 
and receive protection. Many bury themselves in the 
ground, and are thus out of the sight and reach of their ene¬ 
mies. Others, again, form their cocoons on the trunks of 
trees, mimicking the bark so closely that detection is almost 
out of the question. Of these, I may mention the Puss 
(Dicranura Vinula) and the Kitten (Z). Furcula), and also 
the remarkable pup® cases of the family Psychidce. Others, 
again, make their cocoons of tough materials. Of these 
the Fox ( Bombyx JRubi) is an example. The cocoon of the 
Emperor ( Saturnia Carpini) is well deserving mention. It 
