John R. Silber, who has made a number of controversial remarks while running for the Democratic gubernatorial nomination in Massachusetts, has done it again -- and if his rivals have their way, the resulting uproar will not fade away by the Sept. 18 primary.

At a candidates' forum last week, Silber said a proposed abortion rights amendment to the state constitution would allow a woman to kill her baby at birth.

The amendment, supported by Silber's two primary rivals -- Lt. Gov. Evelyn Murphy and former attorney general Francis X. Bellotti -- would allow a woman to obtain an abortion throughout the first 24 weeks of pregnancy "or at any time to protect her life or health or in case of rape or incest." It is being considered by the state legislature.

Silber, who supports abortion rights, said the language of the amendment "means that a woman could go off in private and have her baby in the ninth month and kill that baby. I'm not going to give any woman that right." He called the amendment "a piece of nonsense and the people who support it should recognize that."

Silber has been defending those remarks since.

Murphy has called on Silber to drop out of the race because of his "disgusting comments." She accused him "not only making a spectacle out of himself, but a spectacle of this state."

"I can understand why she wants me to drop from the race," Silber retorted this week. "That's the only way she or Frank Bellotti would have a chance to win."

Abortion has not been a dominating issue in the Democratic primary because all three candidates support abortion rights. Silber said that Murphy, who is trailing in the polls, "is trying to push the abortion issue to a ridiculous extreme . . . to distract attention from the critical issue of her involvement" in the administration of Gov. Michael S. Dukakis (D).