Did you know that it is illegal to roller skate on most parts of Circuit avenue in Oak Bluffs? Or that all raw milk and cream sold in Edgartown is supposed to come from cows certified by the town inspector of milk?

And don't even think about driving your horse at a furious or immoderate gait in Tisbury or at an unreasonable rate in Oak Bluffs. Both are also illegal, and could net you a fine, or worse, a night in jail.

These are just a few among a long list of mostly outdated town bylaws that can be found on the books in Island towns.

Some, such as the horse laws in Tisbury and Oak Bluffs, hark back to a different era, when they were both enforceable and necessary. A closer examination takes the reader back to a much less politically correct era when the laws were clearly focused to protect the rider, instead of the horse.

The Tisbury bylaw prevents a person from riding a horse too fast in order to prevent injury to any person standing, walking or riding on the same roadway; while the Oak Bluffs law is intended to protect anyone "properly" using any street.

While some of these bylaws at first blush seem straight from an episode of Leave it to Beaver, some in fact have a practical application to this day, said Oak Bluffs police Lieut. Timothy Williamson.

Oak Bluff bylaws that prohibit crying the wares - in other words peddling or selling - including ice cream and fish, do serve a real purpose, as does another bylaw prohibiting games involving ball playing and missile throwing in the streets.

This law prohibits any game "in which a ball, missile, Frisbee, [or] bean bag" is used on several streets, including Circuit and Kennebec avenues.

"We actually enforce that one all the time," Mr. Williamson said, adding: "We frequently come across people playing games with balls and remind them that there is a nice long stretch of open park space just a few blocks over."

And while another law prohibiting grazing cow, horse, swine, sheep or goat in any public park, road or way in town is almost never enforced, Lieutenant Williamson said it is certainly a sensible policy to ban animals from grazing in public places.

In Tisbury there is an old bylaw that would seem to be impossible to enforce due to its lack of recognition for gender equality. The law prohibits "all noisy assemblages of Boys" - boys with a capital B, for some reason - "or other persons in the highway, street or public places of town."

The law make no reference to noisy assemblages of girls or women.

The bylaw goes on to state that "all persons participating in any such assemblages, or who shall by hooting, hollering, or other loud noises in any street, highway or public place of the Town . . . shall be punished."

The bylaw could, in theory, be legally enforceable because of the inclusion of the phrase "or other persons," explained Michael Goldsmith, a municipal attorney for the law firm of Reynolds, Rappaport and Kaplan in Edgartown.

Some laws, however, are clearly impossible to enforce and are routinely ignored, such as one passed in Oak Bluffs in 1920 that restricts all people from walking through the public streets or parks with bathing suits on.

A useful caveat allows people to wear a bathing suit provided they are covered "to within twelve inches of the ground" by a raincoat, bathrobe or other similar garment.

"I'm not even sure what we would do with that one. If we chose to enforce it there would definitely be a problem," Mr. Williamson said.

A 1924 Edgartown bylaw prohibits children under the age of 16 from playing in the street or public places in the village after 8 p.m.

Edgartown police chief Paul Condlin said the bylaw is unconstitutional.

"I remember when I first started when some of the officers would threaten some of the kids with the curfew law. But that was really only as a joke," the chief said, adding:

"Even if someone told me I had to enforce it, I wouldn't."

One Edgartown bylaw allows the dog officer to impound a female dog in heat if she is causing a disturbance in the neighborhood, while another regulates how long a driver can coast in his or her automobile without touching the gas throttle.

"I think that one dates back to when all cars had clutches," speculated Chief Condlin, adding: "Or maybe it has something to do with World War II. I'm not even sure."