17 
less in its larval condition,although having the power of locomotion, 
it is still more so now, as its position is simply that of a waiting 
one, generally fixed in one position. The pup of butterflies are 
generally attached to the underside of a leaf, those of the moths 
are either enclosed in cocoons or else buried in the ground. Several 
of the pupe of butterflies have been found to possess the power of 
adjusting their colours to those of their surroundings, notably that 
of the Peacock butterfly (Vanessa Io) which appears in two forms, 
the common form light grey, and the rarer bright yellowish green. 
The pup of nearly all the members of this family have brilliant 
spots of burnished gold on the pupa case. In aseries of interesting 
experiments on the pup of the Small Tortoiseshell, Mr. Poulton 
found that this species was very susceptible to surrounding colours. 
By the use of black surroundings in the caterpillar state, he found 
that the pup# were, as arule, extremely dark, with only the smallest 
trace of the golden spots. On using white surroundings, the very 
opposite result was produced. The black colouring matter, asa 
rule, was absent, and there was a great development of the golden 
‘spots, so that in many cases the whole surface of the pupe glittered 
‘with a metallic lustre. The pupe of 4. Iris (Purple Emperor) 
although of considerable size, is protected by the effect of shadow 
gained by an arrangement of colour. It spins up on the under 
side of a sallow leaf. Last year I had a caterpillar sent up from the 
New Forest, and with the help of Colonel Le Grice, I was fortunate 
enough to rear it. It was very difficult to distinguish from the leaf, 
the effect of the colour being to give it a flat appearance. 
The cocoon spun by the caterpillar of the Emperor moth is very 
interesting. It is pear-shaped, and composed of brownish silk, and 
is so constructed that the newly emerged moth can easily walk out 
of the small end without breaking a fibre, while the entry of an 
enemy from without is impossible. The manner of constructing it 
is that a number of stiff threads are made to project from the small 
end of the cocoon, and these converge as they pass outwards, so 
that the ends are all near together. The other portions of the 
cocoon are of compact silk, and any insect intruder that ventures to 
enter by what we may term the open end, is met by a number of 
spikes, as it were, that repulse it at every attempt. The cocoon of 
the Puss moth is made of far different material. The caterpillar 
spins up on the bark of willow trees, and makes a covering for 
itself out of small pieces of the bark, which it makes sc like an 
ordinary excrescence, that it is very difficult to detect. The con- 
sistency of the cocoon is so hard that it is difficult to pierce it with 
a knife. How, then, does the moth escape. As soon as the moth 
emerges from the pupa case, it ejects a fluid, and softens one end 
of the cocoon, and thus makes a small hole out of which it slowly 
