produced at low cost, so that one has no assurance that a souvenir textile is actually dyed with molluscan purple.
The Mediterranean area and the west coast of Africa were not the only regions where mollusks were used for dyeing. In the British Isles the art seems to have been known from very early times. The Celts of England and the Lake Dwellers of Ireland (about 1000 B.C.) used the common Thais lapillus which is also abundant on New England shores. As late as the eighteenth century this species was used for marking linen in England, Scotland, France and Norway. The French used molluscan purple to dye the parchment of rare books, some examples of which are still bright after 800 years.
Had the Phoenicians possessed the compass and ventured to the West Indies, they would have marveled at the abundance of our Wide-mouthed Purpura, Purpura patula, and its large production of rich violet dye. Collectors who have put live specimens in a cloth bag will recall the bright, durable stains that have appeared soon afterward in the fabric. Many shell collections contain this species in which specimens still retain purple stains on the outside of the shell. The subspecies, pansa, was used in prehistoric times for dyeing cotton on the northwest coast of South America and the west coast of Central America. Even today the Tehuantepec Indians of Mexico use the Pansa Purpura for dyeing cotton threads. The natives have put into effect a plan of conservation and, instead of crushing the shells, they carefully “milk” the living specimens by pressing in the animal to squeeze out the juice. They then return the mollusks to the rocks and revisit them at a later date. The cotton threads are individually drawn through the liquid to obtain the fast dye.
In 1711 Reaumur accidentally discovered that the egg capsules of Thais lapillus were a simpler and more abundant source for the purple dye. As Murex egg capsules mature, they take on a characteristic purplish hue. It is possible that this was the secret, if such existed, that the Tyrians guarded so jealously. Latest experiments indicate that the purple dye is a derivative of indigo containing bromide.
Probably most, if not all, species of Murex, Thais, Purpura and other members of the Muricid family produce this bromide, dye-giving secretion. It has been suggested by some workers that this secretion serves as an anesthetic on various oysters, clams and chitons upon which they prey. However, the presence of purpurase in the egg capsules does not favor this view. In addition, the dye-producing gland is closely associated with the reproductive system and not with the salivary glands or any other organs of the proboscis. Many other carnivorous families which attack other living mollusks in a manner similar to that of the Muricids do not produce this dye.
Inks and dyes are produced by many other mollusks, the Sepia cuttlefish being an outstanding example. Purple dye has been recorded in the Purple
