Work has been carried out for a number of years on the development of a new and improved embryo culture technique to supplement or replace the traditional in vitro methods. This new method is based on the implantation of hybrid embryos onto naked Hordeum endosperm placed on a normal growth medium. In 1972 this method was used in the hybridization of Hordeum X Triticum and 28 (70 %) hybrid plants were obtained from 40 embryos. In 1973 83 (50 %) hybrid plants developed from 167 embryos derived from Hordeum X Agropyrum crosses. The survival rate in Hordeum X Secale crosses has been increased to 30–40 % by the use of this method compared to about 1 % with traditional in vitro embryo culture. An experiment with barley embryos showed that all embryos ≤ 0.2 mm survived in vivo/vitro culture independent of the composition of the growth medium, whereas similar embryos subjected to in vitro culture showed normal development only when grown on a complete medium supplemented with 25 % coconut milk. It is concluded that the composition of the basic medium is still of importance in in vivo culture of hybrid embryos on Hordeum endosperm.