. . . . . . . . "1731" . . . . . . . . . . . "John Walker (natural historian)" . "Rev Prof John Walker" . . . . . . . . . . . . . . . . . . . . . . "John Walker (natural historian)" . . "1803" . . . "John Walker" . "John Walker (natural historian)" . "Very Rev John Walker" . . . . . . . . "Rev Dr John Walker" . . . . . . . . . . . . . . . . . . . . . . . "1803-12-31" . .