| The urachus is a remnant of allantoic origin, connecting the embryonal cloaca to the allantois during early intrauterine life. |
| The embryo forms an allantoic placenta, as is true of at least some peramelids and koalas but not other marsupials. |
| The primary route of transmission is through the ingestion of placenta or allantoic fluids from an infected female. |
| It unites with the common stem of the allantoic and vitelline veins in front of the liver. |
| As the allantois increases in size and importance, the allantoic vessels are correspondingly developed. |
| Each of the strains is separately inoculated into the allantoic cavity of chicken embryos with neomycin solution equivalent to 0.5 mg per egg. |
