| The allantoic cavity persists, but the allantois only covers the placental area of the chorion. |
| The primary route of transmission is through the ingestion of placenta or allantoic fluids from an infected female. |
| Each of the strains is separately inoculated into the allantoic cavity of chicken embryos with neomycin solution equivalent to 0.5 mg per egg. |
| The allantoic arteries in the cord wind in a spiral manner round the allantoic vein. |
| The urachus is a remnant of allantoic origin, connecting the embryonal cloaca to the allantois during early intrauterine life. |
| Repeated inoculation with allantoic fluid obtained from the first passage was carried out to determine pathogenicity. |
