The heat was intense there and innumerable flies, gnats, and mosquitoes assailed him.

The mosquitoes were so fierce that they drew blood from his face a half-dozen times.
Alone in the heat of the deep marshy wilderness he felt fear more than in battle.

Danger threatened here in a mysterious, invisible fashion and he could only wait.
He saw a bush move again, but much nearer, and then came the crack of a rifle.

If his horse, alarmed perhaps, had not thrown up his head suddenly, and received the bullet himself the lad's career would have ended there.
The horse made a convulsive leap, then staggered for a few seconds, giving his rider time to spring clear, and fell among the bushes.
Dick dropped down behind him and quickly unstrapped the rifle from the saddle, meaning to use the animal's body as a breastwork against renewed attack.
His fear, the kind of fear that the bravest feel, had been driven away by rage.

The killing of his innocent horse, although the bullet was intended for him, angered him as much as if he had received a wound himself.