“ The requisites necessary to make tenancy by the curtesy are: (1) a legal marriage; (2) an estate in possession of which the wife must have been actually seised; (3) issue born alive and during the mother’s existence, though it is immaterial whether the issue live or die, or whether it is born before or after the wife’s seisin; in the case of gavelkind lands the husband has a right to curtesy, whether there is issue born or not; but the curtesy extends only to a moiety of the wife’s lands and ceases if the husband marries again. ”