“Whenever possible, isolation via the propagation of virus on chorioallantoic membranes of chicken embryos should be used as the definitive diagnosis of choice.”

“These differ from the chorioallantoic placentae of placentals, however, in that they have no villi, which effectively reduces the intimacy of contact between fetus and mother.”

“Smallpox virus lesions on the chorioallantoic membrane of a developing chick.”

“Unlike the hydatidiform moles, choriocarcinomas and placental-site trophoblastic tumors lack chorionic villi.”

“Amniotic fluid, chorionic villi, or fetal serum can be tested for evidence of West Nile virus infection.”

“The physiological site of the defect in these mice, the chorionic placenta, is found only in therian mammals.”