The Murex Shells. Rock Shells 



varices is significant: it means comparative starvation for the 

 mollusk, which instinctively strengthens the edge of the shell 

 when threatened with short rations. The most gaily decked 

 murex, therefore, confesses to the greatest struggle for enough 

 to eat. Richness of apparel is the badge of poverty and 

 privation. 



Notice the varices on a number of Murex shells. Some are 

 low ridges, scarcely emphasised by tubercles. The majority of 

 species have these knobs prolonged into spines, horns or leaf- 

 like expanses, short and stout, or oftener long, slender, simply 

 or intricately branched. The largest varix fringes the outer lip. 

 Distinct spiral ridges sculpture the spires on every whorl. 



The shells are solid, and limy, lined with smooth enamel, 

 never pearly. That part of the outer varix which interferes with 

 growth is eaten off by an acid secretion to make way for the 

 next one. 



The colouring of Murex shells is usually rich, the lining flesh 

 pink in many species. The collector of Murex has a long and 

 interesting road to travel, and he has a cabinet of very showy, 

 large, handsome shells for his pains. For some rare species he has 

 had to pay a good price. Some commercial value attaches to 

 Murex shells used by cameo-cutters and makers of fancy shell 

 articles. The flesh of two species is eaten by the peasants on 

 the Adriatic shores. 



"The "Tyrian purple" of antiquity was obtained from mol- 

 lusks of several species of Murex and Purpura. Press the oper- 

 culum of our humble purple, and a dull red fluid is exuded. It 

 comes from anal glands, and is doubtless protective, like the ink 

 of common squids. Not knowing how to get at it, the Tyrians 

 ground the mollusks in mortar-like hollows in the rocks. The 

 fluid was then separated by squeezing the fleshy parts and dis- 

 carding the shell fragments. To this was added five or six times 

 its bulk of water, and twenty ounces of soda to each hundred 

 pounds of the mixture. Evaporation from tin or leaden vessels 

 reduced the dye to the desired strength and colour. Wool dyed 

 in this mixture for a few hours was worth $200 per pound, so 

 expensive was the method of obtaining the colour. The secret 

 of this process, lost in ancient times, was rediscovered centuries 

 later, but the cheaper cochineal and chemical dyes have sup- 

 planted all others. 



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