Read it through once

“As he walks through the bush his step is light, elastic, and noiseless; every track on the earth catches his keen eye; a leaf, or fragment of a stick turned, or a blade of grass recently bent by the tread of one of the lower animals, instantly arrests his attention; in fact, nothing escapes his quick and powerful sight on the ground, in the trees, or in the distance, which may supply him with a meal or warn him of danger. A little examination of the trunk of a tree which may be nearly covered with the scratches of opossums ascending and descending is sufficient to inform him whether one went up the night before without coming down again or not.”