Which part of the alimentary canal has no function?

The process of food digestion, absorption, and evacuation depends on each component of the alimentary canal. 

The digestive system of humans has a small structure called an appendix whose purpose is unknown. 

The appendix is a little pouch that projects from the big intestine and resembles a finger.

Although the significance of the appendix is not fully known, it is thought that it may have once played a part in the digestive process as an excellent bacteria storage area. 

The appendix, however, is regarded as a vestigial organ in contemporary humans, which means that it has gradually lost its original purpose.