pieces should be 3 inches in length. One of the ends should be planed down to a width of 1 inches (the distance between the grooves). Nail the four pieces together and insert in the grooves on each side a cleaned 4× 5 picture negative, the gelatin of which may be easily removed with hot water. Glue to the center of one of the glasses a piece of cork to hold the insect pin, and fasten a piece of wood to the narrow end by a wire nail, which will prevent the glasses from slipping out but will still allow the box to be opened. The boxes are made more attractive if they are treated with dark oak jap-a-lac or stain (Fig. 5).

5. Experiments with living butterflies. Before trying the feeding experiments, the butterflies should be kept for at least twentyfour hours without food. After a butterfly has fed, it should be placed by itself, since the same insect may be unwilling to eat a second time. Have as many students at a time see the feeding as can well do so; this will save time, and fewer butterflies will be needed. The mourning cloak, monarch, and violet tip butterflies are satisfactory for this experiment. Place the butterfly on a stick or other rough object, and put the tiny drop of honey near it. This may be done in a cage, or under a glass jar, or in the open laboratory.

In the latter case the windows should, of course, be closed, and this should also be done while watching the insect fly. The flying and feeding experiments with insects make excellent home work if the pupils can readily obtain the live material. Children in New York City have caught and kept butterflies for several months, feeding them twice or three times a week.

6. Study of a butterfly. - Laboratory study.

A. Regions and appendages.

=

Examine a butterfly and distinguish (1) the front or anterior (Latin, ante before) region called the head; (2) the middle region called the thorax; and (3) the hind or posterior (Latin, post = behind) region known as the abdomen.

1. Which region is the smallest? Which is the widest? Which region is longest?

2. To which region are the appendages (legs and wings) attached?

3. Which region seems to have no appendages?

B. Organs of the head; feeding.

1. Observe two long, slender appendages attached to
the head; they are called antenna (singular,
antenna). State the position of the antennæ on
the head. Describe the shape of an antenna, stat-
ing where it is the thicker (i.e. at the proximal end,
which is next the head, or at the distal end, which is
farthest from its attachment to the head).
2. Near the base or proximal end of the antennæ find
the large eyes. State their position on the head,
their shape, and their size (as compared with the
rest of the head).

3. Demonstration. Take a living or a relaxed specimen
of the butterfly, and with the help of a dissecting
needle find a coiled structure on the lower or ven-
tral surface of the head. It is the sucking tube or
proboscis. Gently uncoil it and describe this feed-
ing organ as to position and appearance.

4. (Optional demonstration or home work.) Place a tiny
drop of honey or molasses diluted with water near
a butterfly. If the insect does not seem to realize
the presence of the sweet substance, touch the pro-
boscis with the needle, or if necessary put the needle
into the coil of the proboscis, and gently unroll it.
a. Describe what you have done to get the animal to eat.
b. Describe the movements of the proboscis.

c. What reason do you find for supposing that the butter-
fly is feeding?

d. What reason have you for thinking that the proboscis must be hollow?

5. (Optional.) Between the two antennæ, and projecting upward in the anterior region of the head, are two slender structures covered with hair; they are the labial palps. In some butterflies the labial palps are inconspicuous. If they show in your specimen, describe them as to their position and appearance.

C. Organs of the thorax; locomotion.

1. How many pairs of wings has the butterfly?
2. Describe a wing as to comparative length, breadth,
and thickness.

3. Hold a butterfly between your eyes and the light, and study carefully the course of the veins in the two wings on one side. Toward what region of the wings (i.e. proximal or distal) do the main veins converge? 4. Bend the veins and the connecting membrane in a wing that is given you.

a. Which is the more rigid?

b. What, then, is one use of the veins?

5. Take a small piece of the wing of a butterfly that is given you and rub the surface with your finger tip. a. Describe what you have done, and state how the substance on your finger compares in color with the color of the part of the wing before it was rubbed.

b. (Optional.) Shake some of the powder from a wing upon a glass slide and examine it with a low power of the compound microscope. The bodies that you see are called scales. At one end of each scale you should find a tiny stem by which the scale was attached to the wing, and at the other end usually one or more notches. Describe the shape of the scales that you are studying, and make a sketch of one of them much enlarged.

6. (Optional home work.) Watch a butterfly in the field as it moves the wings in the act of flying.

a. Will the downward stroke of the wings ten to lower or to raise the body?

b. What effect will the upward stroke of the wings tend to

have?

c. In which of these two directions, therefore, must the butterfly strike the harder and more quickly in order to raise the body in the air?

d. Since the weight of the body tends to bring the animal to the ground, in which direction must the insect strike with the greater force in order to keep itself at a given level in the air?

7. Some butterflies have a tiny pair of front legs that are usually folded against the thorax; so that you need to look very carefully before deciding as to the number of legs present.

a. How many pairs of legs has this insect?

b. Are the legs long and slender or short and thick? c. Is each leg all one piece or is it jointed as in the human body?

d. Examine the lower end of a leg and state how the foot is adapted for clinging to flowers.

D. Make a drawing, natural size, of the upper or dorsal surface of a butterfly. Label antennæ, eyes, abdomen, wings, prin

proboscis, head, thorax,

cipal veins of one wing.

flies, as we shall see later, are constructed on much the same general plan as that of other insects; i.e. their bodies are divided into three re

Adult Stage.

For instance, although other insects have two pairs of wings, no others have these organs so beautifully colored and relatively large. This color of the wings is due (we proved in 6, C. 5) to tiny bodies called scales. If the wing of a butterfly is rubbed, the color comes off and the wing at that point loses its color. To

FIG. 6. Life history of monarch butterfly. (Weed.)