16 BULLETIN OF THE BUREAU OF FISHERIES. 
for the manufacture of pearl buttons, now worn by nearly every individual from the 
cradle to the shroud. The pearly mussels are also valuable in the production of pearls 
at a value of about $364,000 a year, but our concern in this paper is with the adaptability 
of the shells for the manufacture of buttons. 
When the manufacture of buttons from fresh-water shells began in 1891, the yellow 
sand-shell was the first to be used. As the industry grew, the supply of these shells 
soon proved to be insufficient. According to Mr. Boepple, the mucket, pocketbook, 
and black sand-shell were then brought into use, but it was not until 1894 that the 
niggerhead shell was tried. The niggerhead proved to be an excellent shell, with firm 
texture and beautiful luster, while a portion of it was found to be highly iridescent. 
This shell gained rapidly in favor and became the standard of price, while in time the 
valuable but less abundant yellow sand-shells became monopolized by the export trade. 
It was the custom of the early shellers, as now, to gather the river-run of mussels 
and cook out the meats of all, but the shells of only two or three species were saved, 
while the others were thrown away as worthless. The shellers cooked out the entire lot 
of mussels in the hope of finding additional pearls and slugs. The shelling and the 
button industries, therefore, have a history similar to many other American industries 
in that the pioneers wasted large quantities of good material through lack of knowledge 
and experience and while secure in the thought that the supply was inexhaustible. In 
the course of time other shells were brought into use, until now 41 species in all are 
employed in the manufacture of buttons and novelties. 
There are approximately 500 species of fresh-water mussels in the United States. 
The commercial species are practically restricted to flowing waters derived from the 
drainage of limestone regions. Such waters include most of the streams of the Missis- 
sippi Basin and some of those of the Great Lakes and Gulf drainages. Here the mollusk 
finds an abundance of lime, as well as of food, with the depths of water, currents, and 
other conditions favorable to its reproduction and growth. Many species of mussel 
occur in the streams of the Atlantic coast, but their shells are either chalky and eroded 
or else too small and too thin for commercial use. Fresh-water mussels of commercial 
value are not as yet known from streams of the Pacific slope. 
An ideal button shell would have the following qualities: The nacre pearly white, 
or preferably iridescent, free from spots, stains, or colorings; the texture firm through- 
out, neither brittle nor chalky, nor yet too hard; the inner surface smooth; the outer 
surface free from ridges or protuberances; the thickness uniform, with low umbones or 
beaks, and tips relatively thick; the shape flattish, oval; the size sufficient to permit of 
cutting several blanks. There are, however, no ideal button shells to be found. Some, 
valuable for certain desirable qualities, are yet far from perfection in other respects. A 
few approach the ideal, but the same species is not always uniform in quality in different 
rivers nor even in different parts of the same river. 
A given species may yield a good working shell in one river, while in another stream 
its shell shows hard and soft spots, stains, dullness of nacre, or other poor qualities. 
For example, the washboard of the upper Illinois River, while extra large, is badly 
stained; yet the same species, in the lower stretches of this river, though much smaller, 
is flatter and so free from spots as to make a much better material for buttons. The 
muckets of the Kankakee, Wabash, and upper Mississippi Rivers are of extra good 
quality, while in the Illinois and some other rivers they are scarce and of second quality. 
