I. The plaintiff, Binani Properties Private Ltd. (shortened hereafter into "Binani") became the landlord by purchase on August 25, 1958, from the then owner, Rakhal Das Pramanick, of 81 Netaji Subhas Road, Calcutta, (for short, "81" hereafter) of which the first defendant, M. Gulamali Abdul Hossain, a proprietary firm, was the tenant on a rent of Rs. 2,000 a month. The remaining defendants, 21 strong, were the sub-tenants of the first defendant.

By a notice dated March 18, 1959, "Binani's" solicitor, Shri D. K. Mitra, determined the tenancy of the first defendant with effect from the following April's end, mentioning therein four grounds of eviction: (1) default in payment of rent from August 25, 1958, to March 18, 1959, (2) reasonable requirement of the landlord, (3) sub-letting without the landlord's consent, and (4) construction of a permanent structure, the very grounds listed in Clauses (i), (f), (a) and (b) respectively of Section (13) (l), Premises Tenancy Act, 12 of 1956. In case the tenant would fail to quit, as demanded, the solicitor, the giver of the notice, threatened -

"........... my client will take such steps as it may be advised for your eviction holding yo