Fleas, of course - but also names for all the things he saw. We don't.
We are not only ignorant of the way complicated things work - nobody has ever successfully explained to me how radio waves get into a room with all the doors and windows closed - we don't know what to call lots of ordinary things we see, including parts of our own bodies. And we don't even know that we don't know.
I made my discovery years ago, when I was working for a very small newspaper in a very run-down building, and the door broke. Not the door, really - the little contraption up at the top on the hinge side, that looked like a small brass pot and had an arm attached to the door, so when you tried to slam the door you couldn't because it went psshhhttt and made it close softly. Once it broke everybody started slamming the door, and we decide that no matter how little money the paper was making and we were making, that we had to get that little pot thing repaired. Only we didn't know how to get it done - because we didn't know its name. The Yellow Pages were no help. The information operators kept getting confused as we went through out long description and thought we were calling of complain about a breather. The door kept slamming. Finally, somebody decided to call an architect's office - and we found out that the little pot that goes psshhhittt is called a "door check. " And we got it fixed, and would have lived happily ever after - except that now I was on the lookout for new nameless things, and ways to find out what to call them."
That little dimple in the middle of your upper lip, right under your nose, for example. A call to a school of anatomy produced the information that it's called the phyltrum. We couldn't find a word for the little web spaces between your fingers, but the one between the thumb and rest of your hand is called the anatomical snuffbox. The little lines on your wrist are racklettes. And the perineum - the perineum is so important a part of your body that it is more easily described in any desk dictionary than in a family paper, so you should look it up.
Now that you're hooked - if you're ever going to be hooked - on names for nameless things, here is an incomplete glossary.
Agrafe - the wire thing that fits over the cork on a bottle of champagne.
Balk - the piece of ground they don't plow at the end of the field.
Bollards - small posts set up to stop cars from riding on the sidewalke, or stop people from stealing shopping carts from a supermarket.
Calash - the folding part of a baby carriage.
Calks - the little things that project down from horseshoes so the horse won't slip.
Caternary - the big wires that stretch between the uprights of a suspension bridge.
Chela (chelae) - lobster claw.
Choil - that thick part on the blade of a jackknife that lets it bend back into the handle.
Cissing - Gissing is hard to describe. You know how when you ride a train through a rainstorm the window doesn't get wet all over, but instead gets this complicated network of blots and drops and streaks and dryplace? That's cissing.
Clerestory - the little windows over the big windows in old fashioned buses.
Cocarde - the star or other, emblem on the bottom of a warplane's wings that tell you what country it's from.
Cockle - a little piece of candy, like a valentine heart, with writing on it.
Callop - a fold of fat fresh.
Compass rose - the thing on the map that shows where North is.
Cresset - the big cast-iron thing with the lights in outside the doors of banks or fancy government buildings built 50 or 60 years ago.
Croches - the little knobs on deer antlers.
Berm - the space on a canal on the opposite side from the towpath. And more important, the space between the hole and the dirt you throw up when you-re digging the hole. This is an especially useful word because if you ever see somebody digging a hole and the dirt keeps falling back in you can say. "Hey, make a bigger berm."
Gnathion - the point, or end, of your chin.
Gonionback of your jaw bone, the part under your ear.
Tang - the thin handle of a file. The part of the knife blade that fits into the handle. "Tang" meaning a sharp taste comes from this word for a sharp little part.
If you like these words, find more and send them to me. Especially, if there is anybody reading this who knows the name for those little cement things, like barriers five feet long and a couple inches high, that you park your car wheels against in parking lots, send that word to me. Because nobody else seems to know what it is.