Some of the germs of these “catching” diseases, like the germs of typhoid fever, of which we have spoken in connection with our drinking water, are carried in the water or milk that we drink, or upon the food that we eat; and one of the worst carriers of germs is the ordinary household fly.
Not so very many years ago, people did not know that dirt makes people sick. You see, they did not know anything about the disease seeds (germs) that grow so fast in dirt. They did not like to have flies about, because flies look so dirty and bite people and crawl over things and spot them. But nowadays, we will not have flies about because we know that they have been in dirty places where disease germs live, and that one little fly can carry thousands and thousands of these germs on his feet.
Have you ever looked at a fly through a magnifying glass or under a microscope? If you haven’t, try it sometime. You will see that his legs are covered with little hairs; and it is on these little hairs that the germs lodge. They are too small for you to see except with a very powerful glass; but scientists have proved that they are there, and they have found that there are always typhoid germs among them.
THE COMMON HOUSE FLY
As he appears through a magnifying glass.
Did you ever see a fly wipe his feet before he came into the house? No, indeed; and he goes anywhere he pleases, over the bread and into the cream. Yet he was born in dirt and bred in dirt, and he lives in dirty places all the time he is not crawling over your clean things and spoiling them.
Flies are hatched from eggs; and these eggs can hatch only in piles of dirt, such as heaps of manure, or places where garbage and scraps from the house are dumped or thrown. We call the common fly the "domestic" or "house" fly, because he lives only in the neighborhood of houses and barnyards where heaps of manure and piles of dirt are allowed to gather.
When the fly first hatches from the egg, it is a little white, wriggling worm called a maggot, like those that some of you may have seen in decaying meat or fish or cheese. The maggots must have decaying substances to eat and live upon while they are growing, and this is why the eggs are laid in manure heaps and garbage piles.
