Assertion: condor's number | /r/CapableOf | use x-ray photography
Facets:
Source sentences:
text: However, this theory has been refuted by studies of egg shell formation in a number of bird species using techniques such as X-ray photography  which have demonstrated that egg shape is determined in the oviduct isthmus (before shell calcification) with the pointed end caudal (furthest down the oviduct).