It's called going to the dogs.

You get on the MBTA and jerk and chug through Boston's murky underground and the swamps of Revere Beach. After 35 minutes and two changes you emerge at Wonderland Park, a latterday Babylon that is one of about 50 greyhound race tracks in the country.

You pass the Wonderland Ballroom and a mean sub shop on your way to the grandstand. In the backround are the wooden hills and valleys of an amusement park where thrillseekers of a tamer sort celebrate. You follow the sports through a huge parking lot, jammed with Pontiacs, Caddies and Ramblers. You pay your 50 cents, mumble "Yes, I'm 21," and pass through the fateful portals.

Inside are 10,000 followers of Mammon: unworking men, grandpas, stiletto-heeled tooties, indescribables, a sprinkling of M.I.T. professors. They mill around the closed-circuit TVs. The long rows of betting windows, the hot dog and beer stands. They spill out to the open-air section by the track, concentrating most heavily by the finish wire. They wander back and forth eating popcorn, clutching the long "green"--scarecrows stuffed with money instead of straw.

Inside, lines quickly form and disperse at the betting windows. As the dogs, donned in colored, numbered blankets, parade past the grandstand and around the track to the "starting blocks," the unctuous, slightly sinister voice of the announcer calls "Hurry, Hurry, Hurrrry--place your bets." The odds on the big boards in the infield flash with the changing whims of the crowd. Tension mounts as the hounds wait, flash, speed. The rumbling mob roars and fragments as the end approaches. The winning number lights up on the board and the favored of fate make their way to the "Collect" windows.

If it weren't for Swifty a dog race would be little different from a race between eight midget horses. Instead of the classic "They're off!" and the clanging bell soon drowned in the thunder of hooves you hear "Theeeere goes SWIFty!!" and a white, shiny, stuffed, vulgar mechanical rabbit on the end of a pole whirs in front of the hounds, who scramble after in mad pursuit.

But few of the regulars go to the track in order to watch the dogs. The majority of races are sprints, and even the long races are over before you have time to tear your eyes away from Swifty. In the grandstand, clustered around the TVs, the bettors shriek and yell and hoot and cheer for "2" "8" or "5". Almost no one calls the hounds by name (which is unfortunate since some of them are striking: Mayer, Take Me Tonight, Golden Fairy).

The only trouble with the betting is that there's not much to bet on. In horse racing the sharpie has lots of factors to consider--breeding, physical condition, trainer, jock, how heavily the horse has been raced, the frequency of workouts, times, the kinds of races the horse has been in, as well as his record of wins and losses. But with dogs it's the blind leading the blind. Greyhounds run the same kind of race every time: they have a preference for the inside or the outside, the pack or the lead, and there's nothing a trainer can do to change his protege's outlook on life. Times, left to the mercy of Swifty's attraction in a particular race, vary widely. And the dogs work out every day, so frequent racing doesn't dull their edge.

The authorities have made a further contribution to this morass of homogeneity by establishing an arbitrary class system. As determined by their records, the hounds are divided into classes graded from E up to A and pitted only against their peers. Spotting dogs who have just moved up or down on the scale is, however, one way of judging their chances. These estimates and comparisons of overall records allow handicappers to function above the humiliation level, and a "consensus" estimate is made on each of the races in the handy 35-cent program sold at the track.

Even so, one professional handicapper said a few days ago, "You know why I picked that one? Well, his name is Doctor S and my nephew is in the hospital."

Wonderland is at least aptly named. It is a haven for the eternal optimist, the guy who's been down so long it looks like up to him. A mechanic from Kentucky bets on dogs with girls' names. An old man goes through a complicated rigamarole with the serial number on a dollar bill to get his number. A hairdresser's assistant visits a clairvoyant to get her bets for the week.

Others stick to "scientific" betting, putting money on the longest odds. There are enough of these number-watchers to keep the boards jumping as much as from 70 to 1 to 9 to 5 on the same dog in five minutes. An Italian longshoreman plays for big stakes: he puts $2 on the #1 dog in the first race. If he wins, he puts $2 on the #2 dog in the next race. If he wins again, he returns to the #1 dog with $2 in the third race, and so on. But any time he loses, he doubles the sum he bets in the next race, though still alternating between the #1 and #2 dogs. One night he lost every race up to the tenth. With $1,024 on the #2 dog, he almost collapsed when it steamed home first.

Chasing the mechanical rabbit around the far side of the track, the greyhounds seem far removed from the frantic pursuit in the grandstand. Their motives are uncomplicated, instinctual, products of an evolutionary trail springing in ancient Egypt and exploited by their upbringing on one of the 200 or so kennels in this country.

Giving a hound the once-over makes you think of both Jim Ryun's slender power and Mohammad Ali's dense bulk. Ribs stick out all over, but so do muscles. Twiggy bigjointed legs. Deer eyes, Teacup muzzles sheathed in leather. Deadleaf ears.

As pups greyhounds are trained in the ways of racing, whipped into good physical shape, and put onto the track at one year. By two and a half they hit their prime, and after four it's off to the stud farm. They can be bought as pups for prices ranging from $300 to $3000, but sales are rare, since most kennels breed their own pups, and few people who don't race have the money or motivation to buy them.

The dogs have good temperament: affectionate and quiet with humans, they become excited only at the sight of Swifty. But even before the moment of truth there are few horsey hijinks--just a subtle tension.

Out of the blocks they accelerate astronomically, the best reaching 40 to 45 m.p.h. coming around the first turn.

But for most fans the dogs are the least important aspect of a night at the track. Greyhound racing is a participation sport, not a spectator sport, and the participation involves risking a valued belonging. Betting puts an edge on life, brings a vividness costlier than a roller-coaster ride. But why is its thrill worth the money thrown away for it? Less than 28 per cent of the $500,000 bet each night is winning money. But the fans keep coming back, and even though the percentages are against them, they go right on betting.

It's all part of going to the dogs.