THE RELATIONSHIP OF VARIOLA AND VACCINIA VIRUSES. MORPHOLOGICAL  STUDIES ON CHORIOALLANTOIS OF DEVELOPING CHECK EMBRYO.
D000650:Amnion; D000818:Animals; D002642:Chick Embryo; D012106:Research; D012899:Smallpox; D014616:Vaccinia virus; D012901:Variola virus
AMNION; CHICK EMBRYO; EXPERIMENTAL LAB STUDY; SMALLPOX VIRUS; VACCINIA VIRUS