A bill strongly backed by women's rights groups to abolish the criminal charge of adultery was attacked by male lawmakers here yesterday as encouraging sexual permissiveness and threatening the family unit.

"It will have the effect of breaking down family life as we know it and give license to promiscuous fornication," thundered Sen. John J. Garrity (D-Prince George's) during committee hearing on the proposed measure. "We would inherently build in a disrespect for the institution of marriage and the family."

That was about as lofty as he senatorial discourse got, as proponents sought to persuade the panel's skeptics with scholarly historical and constitutional arguments that the crime, punishable by a $10 fine, is a legal anachronism.

"The law is ridiculous," Sen. Howard Denis (R-Montgomery), the bill's sponsor, told the members of the Judicial Proceedings Committee. "It is not enforced. There are no prosecutions."

Denis' remarks were received quietly by the six senators, including one woman lawmaker, Ellen Luff, speaking for the bill on behalf of the Governor's Commission for the Equal Rights Amendment, got a different reception.

After sketching what she said were inequities in the Maryland law treating the sexes differently, she traced the history of the crime from seventh century England. In those days, she said, the penalty was a fine of 100 shillings "and you had to find the man a new wife."

"Not a bad deal," said Sen. Jerome F. O'Connell Sr. (D-Anne Arundel).

"Were there any prerequisites laid down for the new wife?" Sen. John J. Bishop (R-Baltimore County) wanted to know.

"That's what you call a 'second-hand rose,'" said O'Connell.

Undaunted, Luff noted that after the Normans invaded England, the law went unenforced, although adultery could be prosecuted as a nuisance if it was flagrant enough. "The only sanction was penance," she added, a sort of "feeble coercion."

"It's called alimony now," interjected O'Connell.

Adultery was banned by the colonial Maryland legislature in 1715, Luff continued, punishable by a fine of money or tobacco or up to 39 lashes "until blood shows."

The present law, with its $10 fine, was added to the books in 1861, she said. The law specifically requires prosecution in the Circuit Court, the higher tier of the state's two-level trial system.

The last prosecution, in Montgomery County during the 1960s, was thrown out because it was brought in the lower District Court, she said.

With adultery treated as a criminal offense, she said, an offender in a divorce case can plead his Fifth Amendment rights and refuse to answer questions. Abolishing adultery as a crime would force the offender to answer for conduct in civil proceedings, Luff said.

"Are you suggesting a guy who commits adultery thinks about the Fifth Amendment?" O'Connell asked, in what turned out to be a rhetorical question.

"If it was good enough for the English people prior to 1715, it should be good enough for the people of Maryland today," Luff said.

"It's ridiculous to keep a law like this on the books in today's society," declared Peg Wallace, legislative coordinator for the National Organization of Women's Anne Arundel County chapter.

Garrity's remark that repeal would foster "promiscuous fornication" prompted Denis, the bill's sponsor, to assert, "to proponent is advocating adultery."

Throughout the discussion, the committee's lone female legislator, Sen. Margaret Schweinhaut (D-Montgomery), remained silent.

The committee took the bill under advisement.