Conservation by the congenitally blind.
D000367:Age Factors; D001766:Blindness / Q000151:congenital*; D002648:Child; D002657:Child Development; D002675:Child, Preschool; D003071:Cognition; D005260:Female; D005556:Form Perception; D006801:Humans; D008297:Male; D011582:Psychological Theory; D014110:Touch; D014705:Verbal Behavior; D014796:Visual Perception