BY HON. A. NORTON, ML.C,. 43 
be spoken of as conscious mimicry. This classification has 
been suggested by Romanes. In the first-named, the 
imitation, however it arises, depends upon conditions which 
cannot be influenced by the mimic, its shape, colour, 
etc., having been determined before, or at the time it 
began its career in the world. I p-opose to show some 
instances of this kind which are wonderful in their 
resemblance to the objects imitated; they are taken 
chiefly from exhibits in the Queensland Museum. 
I admit at once the difficulty of drawing a distinct 
line of demarcation between the two classes I have referred 
to. This I will try to explain by taking as examples what 
are familarly called the stick, or walking-stick, mantis, 
and the leaf butterfly ; the former is commonly spoken 
of by boys as the ‘“ jackstraw.” This insect has the dull 
brown colouring of a dead twig, but the resemblance. to. 
a dead or leafless twig is largely aided by the attitude 
it generally assumes when resting on the branch of a tree 
or shrub. The leaf butterfly when it flits through the air, 
shows only the upper surface of its wings, and this in no 
way resembles a leat; when, however, it alights upon a 
branch, it raises its wings so that they close together above 
its back. The under surface only is seen when it is in 
this position, and it is the under part of the wings which 
have the colour and markings from which its name is 
derived. The head and upper part of its body are raised 
above the twig, and the front edges of the forewing are 
brought forward until the insect’s head rests against them. 
The back part of the body, on the other hand, lies close 
to the twig, and a small projection from the back of the 
wings just touches it. These represent the leaf stalk, 
and from that point a line of darker colour extends up- 
wards through both wings until it reaches the most 
prominent point of the fore wings, the line becoming 
thinner and fainter towards what thus appears to be the 
tip of a dead leaf. In this case, while the marking and 
colour are similar to the object imitated, the effect would 
not be complete but for the action of the insect. Now, 
the raising and folding of the wings above the body can 
scarcely be regarded as a movement designed to complete 
the deception. The butterfly probably does not know 
