Senator Joseph R. McCarthy yesterday admitted under cross-examination that no written evidence in his subcommittee's files influenced his decision to call Leon J. Kamin '49 before it in January, 1954.

He said that information that Kamin had worked in a government radar project in 1945-46, supplied by either Roy M. Cohn or Francis P. Carr, had caused him to summon Kamin as part of an investigation of Communist infiltration in defense installations.

McCarthy said he could not remember the exact time when the first information about Kamin had first been brought to his attention. The only evidence he had Kamin was a government employee, he also admitted, was general information that he had been employed in a radar project.

To verify this information, he said, Kamin had been called before his investigating subcommittee. He admitted the only questions he asked Kamin about his radar work were to name others in defense work "and that includes radar."

Asked about the decision, made in July, 1953, of his Investigating Subcommittee to investigate subversion in defense establishments, the Senator said no minutes existed of any executive sessions. He and his counsel had discontinued a former practice of writing summaries and had vetoed, because of the expense, a plan to have notes taken.

Examine Security Rules

McCarthy explained that the purpose of the subversion inquiry was to examine the effectiveness of security rules to see if legislation were needed.

The cross-examination ended at 4 p.m. yesterday, and McCarthy left the courtroom immediately. Two other government witnesses were called before the court recessed.

The trial will not resume today, nor will a session be held Monday, Judge Aldrich ruled after consulting with government and defense attorneys. No decision has been reached on a Tuesday session.

Aldrich also permitted Kamin to return to Queens University, at Kingston, Ontario, where he is a research associate in psychology, for the duration of the trial.

The two days of testimony McCarthy thus concluded probably constitute the most thorough examination of his Investigating Subcommittee's practices since the Army-McCarthy hearings of April-June 1954.

Defense attorney Bartlett asked the Senator to discuss different public statements of the purpose of the inquiry for which Kamin was called. He told some of the methods for considering the calling of witnesses, and admitted that no records were kept of executive sessions.

The government had asked McCarthy to describe the various steps of establishing the subcommittee and its rules and to explain the purpose of the subversion inquiry.

Denles University Investigation

Both the prosecution and defense asked McCarthy why he had questioned Kamin about whether he knew any Communists at the University. To both he replied that he thought "Harvard was doing a lot of defense work."

Finding the names of Communists at the University, he said, would help his committee to determine whether they were working in secret defense projects.

He denied he was investigating Harvard itself, and said that his statements about "Fifth Amendment Communists" were part of a general purpose of his own "to remove communists from positions of responsibility wherever they may be found."