Assertion: umbilical cord's allantois | /r/HasAspect | no blood vessels
Facets:
Source sentences:
text: In most marsupials, the allantois is avascular, having no blood vessels, but still serves the purpose of storing nitrogenous (NH 3 ) waste.
text: In most marsupials, the allantois is avascular, having no blood vessels, but still serves the purpose of storing nitrogenous (NH 3 ) waste.