MEANS OF PROTECTION. 35 
July 4th, the third turned into a light purple chrysalis. 
I got thirty more caterpillars, and one chrysalis of a bright golden 
colour on nettle. 
July 5th, two more turned darker purple. 
July 6th, 7th, three more turned, gradually getting darker. 
Thus eight of the nine first found had varied in colour from 
yellowish-green to dark purple, according to the time the caterpillar 
was in the box before it turned. 
‘Then I placed four caterpillars in a bright red box, five in a 
bright yellow box, and four in a bright blue box, leaving fifteen in the 
dull blue box,—two having died from ichneumon. 
These were the caterpillars obtained on July 4th. 
Those in the red box gradually became light purple, while those 
in the yellow box varied from purple back to greenish yellow, and 
those in the bright blue box became a brighter purple. : 
All the caterpillars had evidently been affected by the dull blue 
box, the most marked difference being in the yellow box. 
Many moths resemble common objects, as the Herald Moth 
(Gonoptera libatrix) which resembles a withered leaf with a few 
spots of red and white fungus on it. The antennz being laid back 
close to the body. At the base of each there is a small tuft of hairs 
which cover the bright eyes. 
The Goat Moth (Cossus ligniperda) is like a lump of mud, so that 
not only is it protected by habit in its former stages, but by calemeng 
st often escapes in the perfect form. The larva has a very disagreeable 
smell. 
The Marveil de Jour (Agriopis aprilina) resembles the lichen on 
oak bark. 
The Lime Hawk (Smerinthus tiliz) requires sharp eyes to distin- 
guish it on the green bark of lime trees, when it has just emerged. 
Habit is of more use than colour in protection, and in some in- 
stances we find that both habit and protective colouration have been 
adopted. 
The wavy flight of birds and butterflies, rising up and down, or 
flitting from side to side. 
These, however, differ considerably, for while the bird has the 
advantage of speed, the butterflies’ flight is more wavy, as the bird 
moves both wings at the same time, but the butterfly only moves those 
on the same side together, and produces an up-and-down flight much 
slower than the birds’. 
