A tenancy in common is a joint estate without the four unities required in a joint tenancy. The only unity required is that of possession. Like joint tenancies, tenancies in common may be either in fee, for life, or for a terms of years. The holder of an estate in common has full power of alienation, and such an estate descends to his heirs.

"The common law rule was that all estates, acquired by purchase, under circumstances which prevented the presence and existence of the so-called four unities, were tenancies in common.

"The general rule at present in this country, is, that all joint estates are held to be tenancies in common, where they are not expressly made joint tenancies, whether acquired by purchase or descent, except in the few localities where tenancy in coparcenary may still exist. In a tenancy in common, the only unity necessary is that of possession. The estates, the titles, and the times of enjoyment may all be different."