THE PA PIL10NIDI. 
77 
The swallow tail Papilio machaon is a well known butter- 
fly in England, France, and the rest of Europe ; it is also found 
in Asia as far as the Himalayas, and even in South Africa. 
Every one has seen it flying in the fields and resting on the milk 
parsley and other umbelliferous plants, and has admired its great 
size, its yellow wings, marked and splashed with black, and its 
hinder ones so beautifully ornamented with a row of eye-shaped 
spots of light blue. The butterfly appears for the first time 
every year in the month of May and a second time in the month 
of July. 
A very pretty caterpillar, about an inch and a half in length, 
may be found on the wild fennel and carrot plants during June 
and September. It is of a very vivid green colour, and is orna- 
mented with black velvety rings and large dabs of a reddish 
fawn colour. 
When this caterpillar — which is that of Papilio machaon — is 
quietly browsing upon its favourite plant, it resembles many 
others, and there is nothing very remarkable about the insect ; but 
if it be touched it suddenly pokes out a spotted tentacule from 
between the head and the first segment of the body, and there 
being one on each side, they look like horns. Doubtless the 
insect believes that its enemies are alarmed by this proceeding, 
and a faint smell is certainly produced at the same time. These 
horns are common in the caterpillars of the genus Papilio. The 
caterpillar of Papilio machaon has rather a small head, the skin 
of which is not much harder than that of the rest of the body. 
It feeds upon soft leaves, and the mandibles are weak and their 
cutting edge is not toothed. The upper lip or labrum is not 
split, but simply notched, and this indicates that the insect 
browses upon small leaves or upon those which are very “ com- 
pound,” as the botanists have it, and which do not require to be 
held steadily whilst the masticating is going on. The mem- 
branous legs of this caterpillar are evidently admirably adapted 
for a larva that crawls upon easily grasped stems and twigs. 
They end in an inner margin, which is covered with spines, and 
in an outer, which is furnished with little hairs that materially 
assist the sense of touch. 
There are two caterpillars of Papilio machaofi represented 
