"Do you know of a family around here whom no one likes?" asked Ben Gile.
The lanterns were burning brightly out on the lawn of Turtle Lodge, and
Mrs. Reece had just stopped playing so that the children might rest from
dancing. All the lanterns moved gently to and fro on the piazza; the
children were running about, and everybody seemed to be having a
beautiful and breathless time. "Do you know of a family around here,"
called the guide, "whom nobody likes?"
"I do," replied Mrs. Reece, laughing and slapping the side of her face.
"They are just like some people, nagging, annoying, and numerous."
"Do any children here," called Ben Gile, for the third time, "know of a
family nobody likes? For the child who guesses I have a pocket-knife."
"The Smiths!" shouted Peter. "My father says Mrs. Smith is always
quarrelling with the choir."
"Hush!" said Mrs. Reece, seeing danger ahead. "Ben means a family right
here on the piazza."
The children looked at one another, and then Jack turned shrewdly to the
guide. "I guess, sir, it is mosquitoes and flies."
"Good boy, and here's the knife."
Jack thought he had never seen such a wonderful knife. It had three
blades, a corkscrew, a file, and a pair of scissors, and to this day
Jack has that knife.
"Come," said Mrs. Reece, "let us all sit down for a few minutes while
Lizzie is getting supper ready inside."
"How many wings," asked Mrs. Reece, "has a fly?"
"Four," answered Jimmie.
"No," corrected the guide; "a real fly has only two wings. In the place
of the second pair they have queer little knobbed rods which are called
balancers--something like the out-riggers on your scull, Jim. These
steer and steady the fly's body."
"What makes a fly bite?" asked Hope.
"They do not bite, child. A beetle or a grasshopper can really bite,
because beetles and grasshoppers have heavy, horny jaws, toothed on the
edge, with which to do it. But a fly has fine, sharp-pointed jaws. With
these needlelike jaws they pierce a hole in the skin, then with a tiny
sucking-beak, made by the rolled lower lip, they draw up the blood
through this opening."
"I wonder whether any little girl here knows why flies should not be
allowed in the house?" asked Mrs. Reece. No little girl did know
anything except that their mothers were always driving flies out, and
that these creatures buzzed and were a nuisance. "Do tell them," said
Mrs. Reece.
[Illustration:
_A._ House-fly.
_B._ A grown-up mosquito, two larvæ, and a pupa.]
"Well," said the guide, "the fly is such a little acrobat it can crawl
up the steepest and most slippery wall and walk upside down or right
side up with the greatest ease. Perhaps some day you can make a fly keep
still long enough so that you can look at its foot. At the end of the
foot are two little round pads thickly covered with downy hair. On each
side are two sharp claws and many stiff, clinging hairs. With this
flattened foot it can go wherever it wishes.
"But this same little foot is the chief reason why a fly should never be
allowed in the house, for flies crawl into all sorts of dirty places,
and the fine hairs catch and hold the dirt. When the fly lights on us
or on the table, some of the pieces of dirt are shaken off."
"But they are so hard to catch," said Betty; "it takes Lizzie forever
and forever to get them out of the dining-room in the morning."
"I know why they are hard to catch," added Jack, "for I've looked at a
dead fly. They have such big eyes, like lighthouses, they can see all
around."
"Yes," said Ben Gile; "there is no such thing as creeping up on a fly
unawares. Flies are dirty creatures," continued the old man, "and the
time is not very far distant when people will make war on them just as
they do on mosquitoes. Mrs. Fly lays her eggs in unclean places, and as
many as a hundred eggs at a time. These eggs hatch out quickly. It takes
only twenty-one days to make a chicken out of an egg, but to make a baby
fly it takes only a few hours, and ugly babies they are--little white
maggots, or worms, that live and feed and grow rapidly in dirty places.
Within six days the maggot becomes a tiny, dark-brown pupa, and after
five days the pupa hatches out into a grown-up fly."
A dozen little girls at the party made up their minds promptly that
after this evening they, at least, would make war on flies.
"And aren't flies of any use?" asked Betty.
"There is one little fly, Mrs. Tachina-Fly, who is of some use. She is a
cousin of the house-fly. She is of use because she chooses a queer place
to lay her eggs--on the back of a young caterpillar. After these
caterpillars grow and shut themselves up into a cocoon to change into a
butterfly the little fly eggs hatch out into maggots. Of course they are
hungry--all babies are; and finding the nice, fat caterpillar in the
round house, like dutiful babies they eat what is set before them until
the fat, tender caterpillar is eaten up. After they are satisfied they
lie still in their brown skins and change into grown-up tachina-flies,
and at last out come a lot of busy, _buzzing_, bothersome flies. It is
rather hard on the caterpillar. But when we think what harmful, greedy
things most caterpillars are, perhaps it is good that there are
tachina-flies to eat them. Is it time for supper yet?"
"No, not yet," replied Mrs. Reece. "Do tell the children something about
mosquitoes."
"If I had to choose between Mr. and Mrs. Mosquito, I should take Mr.
Mosquito, for he neither bites nor buzzes, but attends strictly to his
own business. Perhaps he thinks Mrs. Mosquito's voice pretty. Perhaps he
likes to hear about her adventures. But most people do not, for they
think Mrs. Mosquito a busybody, always going where she is not wished,
always breaking up conversations, and always coming back after she has
been plainly told that she is not wanted. Yet her singing is music in
the ears of her husband. Perhaps if we had long, slender antennæ, all
covered with hairs, like his, we, too, might like her song. When she
sings these hairs begin to tremble, to vibrate, and a little nerve in
the antennæ changes this trembling to sound.
"In every way Mr. Mosquito seems a more pleasant body. He eats very
little, and contents himself with nectar. But she, knowing that
excitement makes the blood flow faster, and being a hearty eater, begins
her song gently at first, then louder and louder, nearer and nearer.
Finally, with her long, slender, sharp stylets, she makes a hole in your
cheek or your arm, pushes in her sucking-beak, and pumps up the blood.
And there she sucks and sucks until her stomach is full or she is
brushed off or killed."
"Where do mosquitoes lay eggs?" asked Jack, who was certain that
everything in the insect world did lay eggs, as indeed everything does.
"In the water; any puddle will do. When the eggs hatch out they are
funny-looking fellows, long, tapering bodies with a big head end. At the
other end are two little prongs. This baby, like some other babies, is
never quiet, but squirms and wriggles so that it is called a wriggler.
Upon its thick head are two little tufts of hair. These it waves every
moment, so that all the food which comes its way will go into its hungry
little mouth. One of the prongs at the other end of the body is an
air-tube, so that the baby mosquito has to stand on its head to breathe.
It hangs head downward, and holds its air-tube above the surface of the
water.
"When people pour kerosene upon the water the wriggler cannot get any
air to breathe, and therefore dies. Within a few days the wriggler
changes its skin three times; after the third change it looks very
different, and is called a pupa. Now, instead of having an air-tube at
the end, it has two on the back of the thorax. At the tail end are two
flaps to help it swim. Even the pupa is never still a minute, but holds
its air-tubes above the water's surface.
"When anything comes to disturb it, it uses its flaps and swims safely
to the bottom of the pool. At the end of two days out of the pupa skin
comes a grown-up mosquito. If it is a Mrs. Mosquito, she promptly begins
to bite people and to carry about fevers or malaria from person to
person. The bite of a mosquito may sometimes be as dangerous as the bite
of a rattlesnake."
The children had been slapping the mosquitoes buzzing about on the
_piazza_. "And now," said the guide, "before we go into supper, I will
tell you a real and a true story. Mosquitoes sometimes carry sickness
from one person to another until it spreads throughout a large city. We
didn't realize how dangerous mosquitoes were till a short time ago.
People had malaria, and were very ill with it. In some countries many
died. Every one thought, however, that the malaria came in some
mysterious way from the mists of the low-lying swamps and marshes. But
one day some one happened to think it might not be in the marshes, after
all; rather that it might be a certain little two-winged insect with a
short, piercing instrument, which spent its babyhood days in these same
marshes.
"And so two English doctors determined to find out the truth of the
matter. In the faraway land of Italy was a place where thousands of
people were suffering from this disease. There these doctors went and
built a comfortable little house in the very worst place they could
find. They were careful to screen every door and window, and to leave
not a crack for a mosquito to crawl in.
"There they lived, always going into the house at sundown, shutting all
the screen doors, but allowing the damp night air to pour in. It was
this night air which every one supposed gave people malaria. But the two
physicians in the snug little house, free from mosquitoes, kept well,
strong, and happy, although the people outside in the other houses were
very ill and suffering with chills and fever.
"You see, these little Anopheles, for that is their name, bite some one
ill with malaria. Perhaps the next person they stab with their sharp
needle is well. In this way they leave some of the poisoned blood in the
wound. There is another illness which is a hundred times worse than
malaria. This is called yellow fever. In some countries thousands of
people died from this every year, and doctors did not know just how it
was carried from place to place.
"Our Government appointed a commission to study the matter. Dr. Walter
Reed, a surgeon of the United States Army, with three assistants, went
to Havana and built a house, carefully screened, just like that of the
English physicians in Italy. People thought that the fever was carried
in the clothes and on the sheets of those who were ill. To prove that
this was not so, these men wore the clothes of sick people, and even
slept on the sheets taken from the sickbed. They did this disagreeable
thing for twenty days, keeping the little house very warm, and shutting
out the fresh air and sunshine. But in spite of all these things the men
continued well and strong.
"They wanted to prove even more surely that it was a certain kind of
mosquito which really did the harm. So they built another house.
Everything in this house was pure and clean. The rooms were flooded with
fresh air and sunshine. Half of the house was carefully screened and
shut off from the other half. The men in the half that was screened kept
perfectly well. Those in the other half let themselves be bitten by
mosquitoes which had been in the houses where there was yellow fever.
All became dangerously ill with the fever. Two of these brave physicians
died of the fever while trying to find the cause, in order that they
might save the lives of thousands of people."
"That is modern heroism," said Mrs. Reece, "and service of the highest
sort. All humanity is indebted to those brave men. There is no doubt but
that our Panama Canal could not be in progress to-day were it not for
the extermination of the mosquito in the canal zone. Since we can never
tell where a mosquito has been, or what kind of a mosquito it is, I
suppose it is best to keep mosquitoes from biting, and always to keep
them out of the house. And now, children, supper is ready, and after
that games. Let us go to the dining-room!"