No person shall be deemed to have an interest in a tenancy to which the provisions of Section 35, Section 36 or Section 37 apply merely by reason of being joint in estate with any person with whom a contract of tenancy has been made or who has succeeded to the interest of a tenant or who has become a tenant by operation of law or otherwise; and except in the case of a co-widow of a co- tenant who dies leaving no heir entitled to succeed under the provisions of this Act, no interest in such tenancy shall pass by survivorship. Where the persons possessing such interest are joint in estate, they shall be deemed for the purposes of succession to be tenants in common.
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