Judging from the E-mail routing history and CC list -- that stands for carbon copy, children -- I am one of hundreds or thousands or tens of thousands of people reading the Manliness Quiz today. No problem. I reply by firing back another item from my In box, ''Girlspeak-to-English Dictionary.'' (''She says: You have to learn to communicate. English: Just agree with me.'' ''She says: It's your decision. English: The correct decision should be obvious by now.'')

Something is going on here that resembles the flow of water through rock. When rock contains relatively few microscopic cracks, water doesn't get very far. Add more cracks, though, and at a certain point -- the point of percolation -- they suddenly reach a level of interconnectedness that allows a plentiful free flow.

Your own little mailing lists of two or four or six sympathetic souls -- hillary, al, dick, george -- form tiny enough pathways, but they start to interconnect. Where jokes are concerned, the on-line world is percolating.

Naturally we have jokes about sex, jokes about religion, jokes about lawyers, jokes about politics. Because of the still-skewed demographics of the Internet, we have rarefied and Byzantine jokes about computing and jokes about ''Star Trek.'' Much doggerel begins '' 'Twas the Night Before . . . '' or emulates Dr. Seuss. These categories are mixed and matched, as in ''If Dr. Seuss Wrote 'Star Trek: The Next Generation.' '' Horribly morbid disaster jokes appear and spread (Chernobyl, Oklahoma City and even Flight 800 humor) with the kind of astounding timeliness heretofore seen only in tightly knit joke-telling communities of cynical types with access to fast worldwide communication -- namely, stockbrokers and journalists.

Joke-watchers may begin to sense humor surviving and evolving in Darwinian fashion. If recipients don't laugh, the jokes may not get passed forward. Then again, it seems that nothing on the Internet ever disappears, and one can always track down cultural favorites, archived somewhere.

There are Letterman-style Top 10 lists. In fact, there are actual Letterman Top 10 lists, stolen and passed on, along with ever-popular Dave Barry columns. Originality is not a prerequisite. There are just plain lists of all kinds: Dan Quayle Quotations (''Hawaii has always been a very pivotal role in the Pacific. It is in the Pacific. It is a part of the United States that is an island that is right here.''); You Might Be a Physics Major If . . . (''If you chuckle whenever anyone says centrifugal force.'').

Jokes can slosh across cyberspace with a tidal force. One of last year's favorites began:

''VATICAN CITY -- In a joint press conference in St. Peter's Square this morning, Microsoft Corp. and the Vatican announced that the Redmond, Wash., software giant will acquire the Roman Catholic Church in exchange for an unspecified number of shares of Microsoft common stock. If the deal goes through, it will be the first time a computer software company has acquired a major world religion.'' Both Microsoft and The Associated Press felt compelled to issue press releases denying this.

Because E-mail is, sort of, written communication, long-winded text-oriented parodies seem overrepresented. But perhaps this new genre belongs to an oral tradition, too. ''One way in which this stuff is oral, in a sense, is that it has the feel of folklore rather than professionally honed jokes,'' says David Feldman, a popular-culture expert and author. Once there was water-cooler humor and barroom humor. Maybe E-mail chain humor is the ultimate extension -- an electronic bonding experience. ''Its charm is precisely that it is folk humor rather than mass-mediated humor,'' Feldman says, ''akin to graffiti posted in an office that only co-workers would understand.''

In older, slower, more fragmented times, there was traveling-salesman humor. ''I suspect that the notion of traveling-salesmen stories had as much to do with disseminating jokes from one isolated community to another as they did with the proverbial farmer's wife or daughter,'' says Kenneth Fisher, a New York City Council member and, evidently, humor theorist, who sends and receives more than his share. (''Believe me, I've only forwarded a small portion of the flow,'' he says. ''One does not want to develop a reputation for telling bad jokes.'')

Traveling salesman are obsolete. These are fast and not-so-fragmented times. ''I suspect that most of the circulators are also storytellers face to face,'' says Fisher. ''This just gives us more reach.'' Yes -- much more. If the trend continues, it may soon be a matter of minutes from the time a joke is born to the time every human with a modem has received it.