ARTIFICIAL SHELL-DEPOSITS. 249 



found on or near the surface, and among them we find the first attempt of the 

 aborigines at coloring their work." 



Mr. Walker tries to determine the time needed for the accumulation of the 

 different strata, and attributes, as the result of his calculations, an age of one 

 thousand years to the oldest shell-heaps. Yet, he is far from making any positive 

 assertion. "There are so many possibilities to be encountered," he says, "that 

 the question of age is lost among them. The growth of a shell-heap depended, 

 of course, upon the number of people living in the vicinity, the circumstance 

 whether their residence was continuous or occasional, the abundance or scarcity 

 of shell-fish, and many other accidents too numerous to mention. Layers of soil 

 in different parts of the same heap show that portions of the mass ceased to 

 grow for long periods of time, while thick strata of clean shell indicate the rapid 

 and continuous growth of other portions. Future investigations may throw 

 more light on this subject, at present involved in doubt and mystery."* 



Alabama. — Among other shell-heaps on the coasts of the Gulf of Mexico, 

 I will only refer to those on the Mobile River, Alabama, described by Messrs. 

 A^ S. Graines and K. M. Cunningham. 



They allude to the great number of such deposits on the banks of that 

 river, especially upon Simpson Island, which forms the delta between the mouths 

 of the Mobile and Tensas Rivers. " Many of them are the sites of market- 

 gardens, and the shells from those most accessible to the water have been utilized 

 in paving the stock-yards of the railroads, and the grounds around the cotton 

 warehouses in Mobile. The one chiefly examined is about nineteen miles above 

 Mobile, on the land of the Mobile and Ohio Railroad, and two hundred feet 

 from the water's edge. The heaps are composed almost entirely of clam-shells, 

 although a few specimens of Area incongrua, Neritina, Ilelania, and Ft(Si(s chv- 

 ereus are met with."f 



There were also found portions of fourteen human skeletons, pointed bone 

 implements, thousands of fragments of pottery, and even five entire vessels, 

 now in the National Museum. 



California and Oregon. — Mr. Paul Schumacher's reports on explorations of 

 shell-heaps and village-sites on the coasts of California and Oregon, and on the 

 Santa Barbara IslandsJ are known to all who take an interest in North American 

 archsBology. In view of the many facts presented by the explorer, it would be 

 a rather laborious task to give a resume of his results. Fortunately, however, 

 Mr. Schumacher himself has published in German a short article — " Observa- 



* Walker : The Aborigines of Florida ; Smithsonian Report for 1881 ; p. 677, etc. 



f Gaines and Cunningham : Shell-Heaps on Mobile River ; Smithsonian Report for 1877 | p. 290. 



t See p. 119, note. 



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