illar of
the Pieris, the common Large White Butterfly whom we all know (Pieris
brassicae, Lin.). This caterpillar feeds indiscriminately on the leaves
of all varieties of cabbage, however dissimilar in appearance: he
nibbles with the same appetite red cabbage and broccoli, curly greens
and savoy, swedes and turnip-tops, in short, all that our ingenuity,
lavish of time and patience, has been able to obtain from the original
plant since the most distant ages.

But what did the caterpillar eat before our cabbages supplied him with
copious provender? Obviously the Pieris did not wait for the advent of
man and his horticultural works in order to take part in the joys of
life. She lived without us and would have continued to live without us.
A Butterfly's existence is not subject to ours, but rightfully
independent of our aid.

Before the white-heart, the cauliflower, the savoy and the others were
invented, the Pieris' caterpillar certainly did not lack food: he
browsed on the wild cabbage of the cliffs, the parent of all the
latter-day wealth; but, as this plant is not widely distributed and is,
in any case, limited to certain maritime regions, the welfare of the
Butterfly, whether on plain or hill, demanded a more luxuriant and more
common plant for pasturage. This plant was apparently one of the
Cruciferae, more or less seasoned with sulpheretted essence, like the
cabbages. Let us experiment on these lines.

I rear the Pieris' caterpillars from the egg upwards on the wall-rocket
(Diplotaxis tenuifolia, Dec.), which imbibes strong spices along the
edge of the paths and at the foot of the walls. Penned in a large
wire-gauze bell-cage, they accept this provender without demur; they
nibble it with the same appetite as if it were cabbage; and they end by
producing chrysalids and Butterflies. The change of fare causes not the
least trouble.

I am equally successful with other crucifers of a less marked flavour:
white mustard (Sinapis incana, Lin.), dyer's woad (Isatis tinctoria,
Lin.), wild radish (Raphanus raphanistrum, Lin.), whitlow pepperwort
(Lepidium draba, Lin.), hedge-mustard (Sisymbrium officinale, Scop.).
On the other hand, the leaves of the lettuce, the bean, the pea, the
corn-salad are obstinately refused. Let us be content with what we have
seen: the fare has been sufficiently varied to show us that the
cabbage-caterpillar feeds exclusively on a large number of crucifers,
perhaps even on all.

As these experi