The earliest of the five towers was built by the Modi family something more than 200 years ago, and it is now reserved to the heirs of that house; none but the dead of that blood are carried thither.
The origin of at least one of the details of a Parsee funeral is not now known--the presence of the dog.

Before a corpse is borne from the house of mourning it must be uncovered and exposed to the gaze of a dog; a dog must also be led in the rear of the funeral.

Mr.Nusserwanjee Byranijee, Secretary to the Parsee Punchayet, said that these formalities had once had a meaning and a reason for their institution, but that they were survivals whose origin none could now account for.

Custom and tradition continue them in force, antiquity hallows them.

It is thought that in ancient times in Persia the dog was a sacred animal and could guide souls to heaven; also that his eye had the power of purifying objects which had been contaminated by the touch of the dead; and that hence his presence with the funeral cortege provides an ever-applicable remedy in case of need.
The Parsees claim that their method of disposing of the dead is an effective protection of the living; that it disseminates no corruption, no impurities of any sort, no disease-germs; that no wrap, no garment which has touched the dead is allowed to touch the living afterward; that from the Towers of Silence nothing proceeds which can carry harm to the outside world.