president’s address. 
155 
distribution of the large wingless birds, the Emus and 
Cassowaries, in South America and Australia, pointing to some 
connection between these lands in the remote past. 
Butterflies afford many examples of protective resemblance. 
One of the best known is that of the Kallima inachis, an 
Indian Butterfly. This insect makes its appearance during 
the dry season, when the trees are covered with dead leaves, 
and when it settles and closes its wings, the resemblance 
is so close that it is impossible to detect its presence. Those 
who have watched it say that the brilliant fly, which on 
the upper surface is of a dark steel-blue colour, with a broad 
orange-band across the upper wings, suddenly vanishes, 
or in other words, settles and becomes invisible. Now it 
is worth while just to observe the way in which this protective 
resemblance is worked out. In the first place, it will be 
seen that no two specimens of this Butterfly are exactly 
alike on the under side. On the upper side there is no 
variation. This variability of the protective surface is 
doubtless to adapt it to the variations shown in dead leaves. 
One specimen will be of a uniform yellowish brown tint, 
another will be mottled all over with cinnamon-coloured 
spots ; this variation adapts the fly to those leaves which 
have been attacked by a rust-coloured fungus. A third 
specimen has black spots dotted all over its wings to liken it 
to a black fungus. Running across both wings obliquely 
from what is called the anal angle to the apex, is a line which 
corresponds with the mid-rib of the leaf. From this project 
parallel lines on either side which correspond with the lateral 
veins of the leaf. Then in every case there is what at first 
sight looks like a small hole drilled through the centre of the 
upper wing. This is not really a hole, but only a portion of 
the wing-membrane, on which there are no scales on either 
side. Such holes which have been made by Caterpillars, are 
frequently found on dead leaves. Then again look at the 
shape of the wings, how exactly the contour of the two 
