Assertion: emperor penguin's feather | /r/HasProperty | plumule
Facets:
Source sentences:
text: While the density of contour feathers is approximately 9 per square centimetre (58 per square inch), a combination of dense afterfeathers and down feathers (plumules) likely play a critical role for insulation.
text: inch), a mixture of dense afterfeathers and down feathers (plumules) probably play an essential position for insulation.