The attorney for James D. Cronin spent two hours yesterday questioning Partricia Welch, a former Cronin's waitress now on strike in Middlesex Superior Court.

Welch is a member of the Harvard Square Waitresses Organizing Committee (HSWOC) against which Cronin has brought suit to prevent their continued picketing of his restaurant.

The testimony of Welch and of Ann Erdmann, another member of HSWOC, disclosed that members of more than 20 different groups have participated in the picket line. The groups include the Cambridge Ministries, the Cambridge Tenants Organizing Committee, SDS and Women for Action Against Sexism.

James Gahan, Cronin's attorney, was unable to establish whether the non-HSWOC pickets were acting independently or as part of their respective organizations.

Adams House Collective

Testimony also showed that a number of Harvard and Radcliffe students, including members of the Adams House Collective, have participated in the picketing.

Gahan contended there are three grounds for Cronin's petition for a preliminary injunction. He alleged the waitresses have engaged in unlawful picketing, in unlawful threats to employees and customers, and have presented unlawful demands to Cronin. He contends the waitresses' demands are illegal because they violate the Economic Stabilization Act.

Irrelevant Firing

Gahan is also attempting to prove that Cronin's firing of all eight striking waitresses had nothing to do with the strike. If the firing did result from the strike, as the waitresses contend, the firing is illegal. Gahan refused to comment after court yesterday on Cronin's reasons for firing the waitresses.