Symbolically, Nostromo is mounted in his role of ruler of the cargadores; when
he appears in a subservient role for Captain Mitchell at the end of the paragraph,
he is "dismounted." His "silver" mare prefigures his involvement
with the San Tomé silver in the drama to come, while the "grey"
part hints at the ambiguity of his character, either noble innocent or corrupted
thief.