The eyes of a butterfly are large and of the usual insect pattern—i.e., compound, being made up of a number of tiny lenses, hexagonal in shape, like the honeycomb of the domestic bee. Roughly, about three thousand of these lenses go to make up the two eyes. As pointed out, their range of vision is comparatively short, but within their range vision must be very keen—before, behind, above, and below. I once saw a sparrow try to capture a Large Garden White in a street in the town; he darted at it again and again, much in the manner of the ordinary spotted flycatcher, but the butterfly seemed to have no difficulty in evading him, and eventually he gave up the game.
A small portion of the eye makes a good slide for the microscope, but the individual lenses are hardly visible through an ordinary hand-glass. On the top of the head are one or two small simple eyes, which do not look as if they could be of much service, but one never knows, and the butterflies will not tell, although they have long tongues.
The tongue is a very pretty structure; when not in use it lies coiled up in spiral fashion like a watch-spring, and is then well protected by two little side-covers called the “palpi.” Needless to say, the tongue cannot sting. No moth or butterfly has a stinging organ; the tongue is too delicate for any “cut and thrust” work. It is not difficult to mount a butterfly’s tongue for the microscope, and its examination well repays the trouble. Particularly noticeable under the microscope are the little bell-shaped suckers placed in long rows near the tip. If you wish to make and examine a cross section, take the head of a freshly killed specimen and extend the tongue in a little melted paraffin wax; when this is thoroughly set, cut it across in very thin slices with a sharp razor; place one on a glass slide, then on to the microscope stage, and there you are! You will soon discover that the simple-looking tube is a very complicated affair, and quite a little study in itself.
We will not linger over what remains of the anatomy of our butterfly. The legs are six in number, but occasionally the first pair are useless for walking, and only the middle and last pairs are fully developed. Always remember the maximum number of legs for all insects is six. Caterpillars may have more or less; they occur as footless grubs with no legs at all, while some have as many as sixteen legs.
The last, or abdominal, section of a butterfly’s body carries the sexual organs; it is usually more slender in the males than in the females.
CHAPTER II
THE CAPTURE AND PRESERVATION OF BUTTERFLIES
In the rearing of butterflies from eggs and in watching them all through their larval stages, we learn a great deal concerning their life and habits, and finally secure perfect specimens for the cabinet. But the glories of the chase and the charm of the country ramble weigh more in the balance with the naturalist, and the story of a captured specimen is often far more interesting than the record of a bred one.
Of butterfly nets used in the chase there are many and varied patterns in the market. I made my own and a better balanced one it would be hard to find. Having seen and handled a few in my time, my experience has been that they are mostly too heavy, have too many loose parts, and their weight is badly distributed. Indeed, I saw one lately which felt more like a hammer in one’s hand. I think if you try to get one made after the pattern here described and figured on p. 15, you will not be disappointed with it.
Now, it is one of the avowed purposes of this little book to make the study and collecting of butterflies cost all the time a boy can spare, and little, or, at least, not much in money. The requirements for a ring folding net are 2 yards of steel wire, rather less than 1/8 inch in thickness (cost about threepence); three copper rivets and washers, 3/16 inch by 3/8 inch long (cost one penny); one 1/4-inch iron screw-head bolt and nut (one penny). Cut the wire into two pieces, each 20 inches long, and two pieces 16 inches long. If you can get a tinsmith friend to turn the eyes for you, so much the better; you will thus avoid the most difficult part of the operation, but you would lose some valuable lessons and the satisfaction of having made the whole thing yourself.