Sentence 1: Anteriorly , it rests on the dorsal surface of the anterior medullary velum , and its white substance is continuous with that of the velum .
Sentence 2: It rests on the white surface of the dorsal velum , and its former medullary substance is continuous with that of the velum .
Question: Do Sentence 1 and Sentence 2 express the same meaning? Yes or No?