Among all of the technological advances, the primitive bayonet was still used in World War I. The bayonet is simply a long knife attached to the end of the rifle. Bayonets were useful in the close-quarters combat in the trenches. Bayonets often were given to the soldiers whose job it was to protected the grenadiers. Even in close combat, the bayonet saw little usage as hand knifes, spades, or clubs were often used by the soldiers instead:
"But the bayonet has practically lost its importance. It is usually the fashion now to charge with bombs and spades only. The sharpened spade is a more handy and many-sided weapon; not only can it be used for jabbing a man under the chin, but it is much better for striking with because of its greater weight; and if one hits between the neck and shoulder it easily cleaves as far down as the chest" (Remarque 104).
One problem that the bayonet caused was that it was often difficult to remove the blade from the victim, so the attacker was struggling to free their weapons so they could keep fighting:
"a man has to kick hard on the other fellow's belly to pull it out again; and in the interval he may easily get one himself" (Remarque 104).
The French made very slender bayonets, or 'needle' bayonets.
The Germans made bayonets with a saw edge on one side. It would cut smoothly in, but the serrated edge would widen the wound on the way out. Or the other way around, depending on the blade.
"We overhaul the bayonets...that have a saw on the blunt edge. If the fellows over there catch a man with one of those, he's killed at sight" (Remarque 103).
This saw-back bayonet was a big deal to the propaganda aspect of the war, because of the image of sharp, jagged teeth and the idea of being sawed to death was so brutal. The saw-back bayonets were actually helpful in Anti-German propaganda.
The Germans also made an adapter that would attach enemy bayonets to German rifles, so captured bayonets could be used. In the picture above, the German's have Russian bayonets on their rifles.