Salt-glucose mixtures are replaced by amniotic fluid from the same embryo from which the. tissues are obtained. An eggshell sector about 1.25 inch in diam. is cut from the large egg pole on the 8th-9th day of incubation, and the contents poured cautiously into a petri dish so as to avoid bursting of the delicate amniotic membrane. Then 2-3 cc. of amniotic fluid is obtained by canula. Tissue for explants is cut out and the remaining embryonic tissue provides the amniotic juice. The culture medium consists of embryonic juice and amniotic fluid 11.