Read it through once

Yet even in the time of Homer the sense of humanity seems to have decided against poisoned arrows as being both unnecessary and cruel, just as, in our own times, explosive bullets have been condemned, and are no longer used by civilized nations. But we should remember that until man became so expert with the bow and spear and so civilized by tribal fights as to be able to do without poisons, they were a very useful help in the struggle for civilization. Hundreds of thin pieces of bamboo about six inches long were regularly carried by certain African tribes. When dipped in poison and afterwards placed in paths in the ground, they formed a very efficient protection against barefooted enemies.