Chapter 2

THE FEET OF THE FLY. (March 11, 1842)

1. It will not have escaped your notice, and you will have seen quite often how the fly, with its six little feet, patters forth so agilely on a highly polished vertical surface as well as on a horizontal table or plane.

2. But how is this possible for this animal, since its feet, although each one terminates with two very small pointed claws, are still smooth on the outside?

3. See, that is already something miraculous, considering that on a vertically standing, highly polished surface, not even the lightest down feather can remain hanging without being glued on! How is it possible for the fly without some means of sticking?

4. Some very active natural scientists have found, with the aid of very powerful magnifying devices, that the fly – and all animals of this kind – have a very elastic little bell attached to its feet between the claws, which it uses as tiny vacuums to thin the air, accomplished in the following manner: when a fly places a foot on the upright surface of a window pane, she sucks in the air inside of a bell, thus the foot, provided with the vacuum of the little bell, is held fast to the surface by the weight of the outer air surrounding the little bell.

5. To accomplish this task, each fly would have to have its own internal air pump! And how fast it would have to operate such an inexpressibly clever mechanical device to satisfy the demands of all six feet in the quick and unpredictable meanderings of the fly?!

6. Obviously, this is hardly feasible, although the fly does in fact possess such visible little bells! But, if the fly does not hold itself in the manner diagnosed by the natural scientists, how does it accomplish this task” – the answer will be very easily perceived from the following presentation.

7. If you have ever, even once, observed a fly very closely, you must have noticed that it is provided with tiny hairs and bristle-like points all over its body. Yes, even the pair of wings on their outermost rim are provided with a large quantity of outward-running ray-like pointed little feathers.

8. What use is all this to the fly? Soon we will have the answer.