The Citizens Emergency Committee to Save Memorial Drive has discontinued its dawn patrols of the Charles riverbank.

The patrols of "Minutemen"--from 5 a.m. to 7 a.m.--were begun in early November to save trees lining Memorial Drive near the Lars Anderson Bridge from destruction by the Metropolitan District Commission. The MDC, which will build three underpasses along the Drive, plans to move some of the trees and cut down others to make room for the underpass at Boylston St.

Edward L. Bernays, co-chairman of the Emergency Committee, said this week, however, that the MDC has not even asked for bids on a private contract to move the trees and that they would be safe until the spring.

Some observers speculated, however, that along with the MDC's sluggishness the cold feet of the early-morning sentries and the complete exhaustion of the Minutemon's publicity-value caused the patrols' suspension.

Bernays, the septuagenarian founder of modern public relations, attributed the MDC's caution to the widespread public support for his anti-underpass position.

He said he will now begin work to "articulate" this public opinion in support of three anti-underpass bills that have been filed in the Massachusetts General Court, the state legislature.

The bills should come before the legislature in the next session, which opens today. A number of anti-underpass bills were defeated in last year's session.