The Assembly. This was the League's Parliament. Every nation who was a member sent a representative to the Assembly. The Assembly could recommend action to the council and vote on: admitting new members to the LoN / appointing temporary members to the Council (beside the permanent members) / the budget to the League / the amendment of the League Constitution / other ideas put forward by the Council. The Assembly only met once a year. Decisions made by the Assembly had to be unanimous - 100% of the votes...

The Assembly: The Assembly consisted of representatives of all Members of the League. Each state was allowed up to three representatives and one vote. The Assembly met in Geneva and, after its initial sessions in 1920, sessions were held once a year in September. A special session of the Assembly might be summoned at the request of a Member, provided a majority of the Members concurred.
The special functions of the Assembly included the admission of new Members, the periodical election on non-permanent Members of the Council, the election with the Council of the judges of the Permanent Court, and the control of the budget. In practice the Assembly had become the general directing force of League activities. (Wikipedia March 2010)