Question: the part of peripheral nerve tissue that forms the myelin sheath is the
[{'answer': 'Schwann cells', 'provenance': [{'wikipedia_id': '19319', 'title': 'Myelin', 'start_paragraph_id': 1, 'start_character': 170, 'end_paragraph_id': 1, 'end_character': 183, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '19319', 'title': 'Myelin', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 997, 'bleu_score': 0.9312237663823941, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16303866702305324675}, 'section': 'Section::::Abstract.'}]}]