ght
in his conjectures. After him, other scientists who have carefully
studied the subject have expressed the same opinion with regard to the
efficacy of large wells.

ALICE D. LE PLONGEON.

Brooklyn, July 15, 1885.

* * * * *

Cholera failed to strike a single one of the 4,000 women employed in
the national tobacco factory at Valencia, Spain, though the disease
raged violently in that city, and the _Medical World_ recalls that
tobacco workers were also noticed to enjoy exemption from attack
during an epidemic at Amsterdam.

* * * * *

THE CABBAGE BUTTERFLY.

A patch of eggs and the minute caterpillars or larvae nearly emerged
from them are seen on the leaf. These tiny eggs are at first quite
white or pale yellow, and form an object for the microscope of
remarkable beauty, which is worthy of the examination of all who take
an interest in the garden and its insect life. An egg magnified is
drawn at the bottom left-hand corner of the woodcut. When the eggs are
near the hatching point they darken in color, and a magnifying glass
reveals through the delicate transparent shell a sight which fills the
observer with amazement; the embryo caterpillar is seen in gradual
course of formation, and if patience and warmth have permitted it, the
observer will witness slight movements within the life-case, and
presently the shell will break and a black head with moving jaws will
be thrust out; the little caterpillar unfolds and slowly crawls away
from the egg-shell, and inserts its jaws into the green leaf. It is
curious to witness how judiciously the little creatures avoid crowding
together, but strike out in different directions, and thus they make
sure of a plentiful supply of food, and distribute the effects of
their depredations. These caterpillars eat continually, and hence
rapidly increase in size, until they present the appearance shown in
our drawing at the bottom of the illustration, which is a full grown
caterpillar.

[Illustration: THE CABBAGE AND PEACOCK BUTTERFLIES.]

It will be observed that this insect is composed of thirteen segments
from head to tail, which is a distinctive characteristic of all
insects both in the larval and perfect states; but in the case of this
and most other caterpillars these segments are sharply defined and
readily recognized. It will also be noticed that the three segments or
"joints" nearest the head bear a p