Vermiform appendix is a vestigial organ in human being give reason.

Vestigial in that sense that the organ seemingly has no functions or useless now but they might have functions previously which are lost someway due to evolution. The human appendix may be considered as a vestigial organ as it has been proved that the removal of the organ after infancy does not create any harm.

Explanation:

Vestigial organs are the organs that have no apparent function and are considered to be the residual parts from the past ancestors.

  e.g: the human appendix,

         the pelvic bone of a snake,

         the wings of flightless birds.

Several biologists support the theory that the appendix is a vestigial organ that was once used by our herbivorous ancestors. It was found that in herbivorous vertebrates, the appendix is comparatively larger and it helped in the digestion of tough herbivorous food such as the bark of a tree.

This structure helps in the proper movement and removal of waste matter in the digestive system, contains lymphatic vessels that regulate pathogens and lastly, might even produce early defences that prevent deadly diseases.