240p8137 A reversion, or "possibility of reverter," after a base fee is not SECTION 220. The Rule against Accumulations is somewhat in SECTION 221. "A reversion is the residue of an estate left in the grantor to commence in possession after the determination of some particular estate granted out by him." If there could be a fee tail (there cannot since the Act of 1855, Sec. 66, supra) the failure of issue in the line of the tenant in tail would justify a reversion to the grantor or his heirs. After an estate for life or for years there is a reversion to the lessor or heirs of the grantor. After a widower's death and following his estate by the curtesy the heirs at law of the wife have a reversion. It is said that a reversion arises from con struction of law and is never created by deed or will as a remainder or executory devise: 21 Corpus Juris, 1018. SECTION 222. It is generally said that a property owner has a reversion in the event of cessation of public use of a street abutting upon his land which justifies a claim of the absolute title to the middle line of what was the street: Paul vs. Carver, 24 Pa., 207; Sec. 413, post. If a railroad right of way is abandoned the owner of the land over which it was condemned claims a "reversion." This may be an improper use of the term for it is said that "the interest of the person who grants a determinable or base fee is a possibility of a reverter": Slegel vs. Lauer, 148 Pa., 245; Sec. 60, supra. ESTATES OF CO-TENANTS SECTION 223. Blackstone enumerates estates: in severalty; in joint-tenancy; in coparcenary; and in common: 2 Blackstone, 179. 200 Pe 24 SECTION 224. The principal incident of joint-tenancy was the doctrine of survivorship. The Act of 1812, Pur., under "Joint-Tenancy," p. 2031, requires that such estates shall be considered to every intent and purpose as estates of tenants in common The Act abolished the doctrine of survivorship except in cases of trust estates of trustees and except where the jus accrescendi is expressly provided for by deed or will: Redemptorist Fathers vs. Lawler, 205 Pa., 24xxx SECTION 225. Estates in coparcenary are practically merged into estates in common: Sec. 14 of Interstate Act of 1834, Pur., 2002; Sec. 19, Intestate Act of 1917, P. L., 441. SECTION 226. At the present time the most important sorts of cotenancies are: in common; by the entireties; and of partners. SECTION 227. Tenancy in common was favored in equity before the passage of the Act of 1812 (Carnes vs. Grant, 5 Binney, 122) and now any conveyance to two or more individuals (other than man and wife), whether by deed or will, constitutes them tenants in common with the unity of possession. SECTION 228. For injury to this possession or interference with the enjoyment by trespass the tenants in common should all join in an action: Shields vs. Penn. Co., 56 P. LJ., 174; Irwin's Adm. vs. 1 vs. Brown 35 Pa., 331. But the tenants do not necessarily have unity of title and therefore one tenant may have his action of ejectment to recover or as f |