The textured web of the Watergate controversy grew more tangled this week amid presidential confessions and dramatic congressional hearings.

President Nixon admitted that he had ignored "staff warning signals" of Watergate cover-up attempts. "With hindsight, it is apparent that I should have given more heed to warning signals I received along the way about the coverup," he said in a statement on Tuesday.

Nixon also said the hearsay evidence of witnesses testifying before the Ervin Watergate subcommittee "could...lead to a serious misunderstanding of those national security activities which, though totally unrelated to Watergate, have become entangled in the case." Despite the growing discreditment of his Administration. Nixon vowed not to resign in face of pressure.

Meanwhile, the Watergate witnesses themselves are challenging the veracity of each other's testimony. James W. McCord Jr., who has implicated "the very highest levels of the White House" in the controversy, was challenged by Gerald Alch, his former attorney.

Alch said last week McCord's testimony was falsified in an attempt to "get Nixon." McCord, a former CIA official, testified of White House pressure to portray the Watergate break-in as a CIA plot. In exchange for corroborating that story, McCord would have received executive clemency, John J. Caulfield, former White House staff testified. The CIA had previously been linked to a 1971 break-in at the office of Daniel Ellsberg's psychiatrist.

Watergate conspirator Bernard L. Barker told the congressional subcommittee he bugged the Democratic National Committee offices "as a matter of national security," in exchange for promises of aid to antiCastro Cuban forces. Barker also participated in the Ellsberg break-in.

The hearings, which began last week, have received continuous television coverage, and are expected to continue through next week.

In related developments, Elliot L. Richardson '41 was confirmed by the Senate as the new Attorney General. Satisfied at Richardson's choice of Archibald Cox '34 as Watergate special prosecutor, the Senate approved Richardson, who fills the post once occupied by John N. Mitchell. Mitchell was indicted last week in connection with an unreported contribution to Nixon's campaign.

With all the indictments surfacing, the first note of real tragedy struck yesterday. Rep. William O. Mills (R-Md.) committed suicide a day after he denied receiving an unreported $25,000 campaign contribution from the Committee to Re-Elect the President.