I think that the cause of this feeling which these apes engender within me is due to their remarkable resemblance in form to our Earth men, which gives them a human appearance that is most uncanny when coupled with their enormous size.
They stand fifteen feet in height and walk erect upon their hind feet. Like the green Martians, they have an intermediary set of arms midway between their upper and lower limbs.
Their eyes are very close set, but do not protrude as do those of the green men of Mars; their ears are high set, but more laterally located than are the green men's, while their snouts and teeth are much like those of our African gorilla. Upon their heads grows an enormous shock of bristly hair.
It was into the eyes of such as these and the terrible plant men that I gazed above the shoulder of my foe, and then, in a mighty wave of snarling, snapping, screaming, purring rage, they swept over me--and of all the sounds that assailed my ears as I went down beneath them, to me the most hideous was the horrid purring of the plant men.