Former state senator Larry Wiser has filed a legal challenge to Maryland's new legislative redistricting plan, charging that in Montgomery County it violates provisions of the state constitution. The most irritating aspect of Wiser's action to some Montgomery legislators, they grudgingly concede, is that he just might have a point.

The new Montgomery districts, drawn to account for population shifts reported by the 1980 census and to protect political careers, look like bizarre zoological mutations, plumping out in spots like a terrier with an elephant's trunk or an alligator with a leg on its head.

Wiser, in a suit filed in the state Court of Appeals, claims that some of these districts--which he asserts stretch in places like "little dog legs"--fail to meet the state constitutional standard of "compactness."

The reason for the unusual shapes is not disputed by Wiser, a Silver Spring resident and lawyer who lost a reelection bid for the state senate four years ago, or the Montgomery legislators. The new boundaries result from a desire to guarantee that no lawmaker seeking reelection this year will have to run in a district where there are more incumbents than seats, while ensuring that the population is distributed evenly among the districts.

Because all but two of the 25 senators and delegates live in the southern half of the county and most of the growth in Montgomery during the past decade has been in the northern half, some of the districts stretch in narrow fingers from where the voters live to where the delegates live.

"Let's face it. Larry may not have the most altruistic motives for filing the suit, but he's got a point," said one top Democratic official who asked not be identified. "When people see that every incumbent lives in the southern half of the county, but all the growth in the past 10 years has been in the upper northern half, they're going to come to the inevitable conclusion that the new map looks--to say the least--a little skewed."

One district--17--runs from Kensington up through Rockville to Gaithersburg. And another, District 19, runs from Gaithersburg to Silver Spring, dropping down like a comma to pick up Sen. Sidney Kramer and Del. Lucille Maurer. The legislator who lives farthest north in District 19 is Del. Joseph E. Owens, a Rockville resident. District 15, running like a bloated boomerang from Gaithersburg down around the county's edge to Bethesda, has four legislators--three, Sen. Laurence Levitan, Del. Judith Toth and Del. Robin Ficker, live in the Bethesda-Chevy Chase area, and the fourth, Del. Jerry Hyatt, lives in Damascus.

The court, in its decision, must rule whether these districts meet the constitutional definition of "compact in form." In a similar suit in 1973, the court master assigned to advise the high court found that the 1970 redistricting plan for Montgomery failed the test of compactness because one district, that of former Republican Rep. Newton Steers, then a state senator, was drawn so that it stretched along the width of the county.

In its decision, the seven-judge court has several options. It could throw the entire redistricting plan back into the General Assembly or substitute its own statewide plan; rule that only a few counties do not meet constitutional standards; or find that only Montgomery County districts do not meet constitutional requirements.

If the Montgomery plan is found unconstitutional, the court could either tell the county to redraw its lines or substitute the alternative plan submitted by Wiser. At least two senators and four delegates would lose their seats under Wiser's proposal.

A number of other counties and jurisdictions are expected to file suit before the March 31 deadline set by the court for all challenges, increasing the likelihood that the court will review the entire redistricting plan.

"Everyone is anxiously biting their nails," said Stanton J. Gildenhorn, chairman of the county's Democratic Central Committee. "Let's face it, if Larry (Wiser) wins, everything will be thrown into total turmoil."

Publicly, most legislators scoff at what they say is Wiser's "white knight" rush to protect the voters. The former senator, most say, is suffering from a bad case of lost election blues and is trying to do through the courts what he couldn't do in an election.

"The fact of the matter is that Larry is an out that wants in," said Sen. Victor Crawford (D-Rockville), who called the present redistricting plan for Montgomery "no worse than any other in the state."

"I wouldn't call his plan too natural either," Crawford continued. "It throws everybody in with everybody else except Larry. Isn't it kind of odd that under his plan he would run in a district without an incumbent?"

Wiser lost in a reelection bid four years ago for a senate seat against Sen. Sidney Kramer in District 19 and admits readily that he has been running for the seat--and a rematch against Kramer--ever since. Legislators charged, and Wiser readily admitted, that he offered to drop the suit if boundaries were redrawn to return his residence to District 19. Under the present plan, Wiser would be just across the 19th District's border in a new District 18 and would face Sen. Margaret Schweinhaut, the senior member of the county's legislative delegation and generally considered a formidable campaigner.

Despite their public attacks on Wiser's motives, county lawmakers, not for attribution, are beginning to have second thoughts about their effort to preserve the seats of all the incumbents.

"Look, I didn't like the process and I don't think the plan is the best one we could have had," said one delegate. "But one of the factors we all considered was protecting our own districts. In retrospect, maybe it wasn't the best thing to do, but it was probably the only thing we were going to agree to do."

According to a number of legislators, the county delegation approved the final plan after months of meetings. The governor's commission set up to redraw the state's legislative districts followed the county's plan precinct by split precinct, incumbent by incumbent, making no changes.

More challenges to the new districts are expected in Montgomery and other counties. Rockville and Gaithersburg are joined together to form District 17, diluting the representation of each municipality. The suburbs of Gaithersburg, with a population of 61,400, are split among four districts.

Gaithersburg officials said they will challenge the redistricting plan on the basis of "compactness," their only constitutional basis for a suit, although their major source of dissatisfaction is the combination of Gaithersburg and Rockville in one district. Gaithersburg leaders said the town of Barnesville plans to contribute funds to Gaithersburg's suit because the two municipalities were formerly in the same district and Barnesville officials are unhappy at being placed in another district under the state plan.

Rockville officials, who at one time supported the plan, have since voted to remain neutral in the suit. The county's League of Women Voters has gone on record opposing the governor's plan for the county and the state branch of Common Cause also has agreed to support Wiser's case, but has yet to make a decision on his alternative plan.

Among the other counties and cities contemplating a challenge to the governor's plan are Baltimore City, St. Mary's, Charles, Baltimore, Talbot and Harford counties and the city of Salisbury. A group of Howard County residents also plan to file suit, according to lawyer Read McCaffrey, who is representing the citizens.