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BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Frequent allusion is also made to pearls attached to the valves of the shell, 
or flattened on one side against them, forming “button pearls,” but rarely of much 
value. 
A peculiar statement is made in a New York paper in connection with this and 
the preceding question. The writer believes that pearls originate from sand grains 
taken in at the mouth, passing into and through the intestines, and lodging in the 
outer edges of the mantle, there causing irritation. Here the larger ones remain, 
while very small ones “pass on and go into a white substance, which I have called 
the pearl bag.” 
It is evident from these accounts that there is no proper reason for the wholesale 
destruction of TJnios that has been practiced in many parts of this country, where 
the pearl-hunting “fever” has extended. Nearly all pearls of any value lie near the 
edge of the shell, and their presence could readily be ascertained by the use of the 
little instruments employed by pearl-seekers in the rivers of Scotland and Germany, 
and the shells not bearing pearls be returned to the water without injury, to propagate 
their species and, perhaps, themselves produce pearls in succeeding years. 
The answers to question 14, as to the sizes, shapes, and colors of pearls found, 
are full, varied, and interesting. Nearly all of the papers reply to the inquiries more 
or less, so that the list of answers numbers 122, more than under any other head; 
although a good many of them are indefinite, and many speak only of some one or 
two of the points covered by the question. 
As to the sizes, some of the responses are given by dimension and others by 
weight. Among much variety there is a fairly general result expressed to the effect 
that the maximum size for round or shapely pearls is about half an inch in diameter 
and about 80 grains in weight. Of course, they range downward to very small sizes, 
sometimes called “seed pearls,” and often compared to pin-heads, bird-shot, mustard- 
seed, etc., and many of the papers assign much lower limits than half an inch for the 
maximum size. Of the papers that describe the larger sizes, several say half an inch, 
five-eighths, seven- sixteenths, etc., and others refer to a bullet, a marble, a large buck- 
shot, and the like, for comparison. A few even exceed these statements, one paper 
saying that pearls range from the size of bird-shot to 90 grains and even 100 grains 
(Tennessee); another (Texas) saying that round pearls are found larger than a 
buckshot, and button-shaped up to the size of a quarter dollar and “up to one inch” 
(Tennessee), while the Ohio paper refers to the irregular “wing pearls” as in some cases 
over 2 inches long. About one-fourth of the papers are indefinite, saying that the 
pearls are of “all ” or “various” sizes, shapes, and colors, with no specific data. 
As to form, there is a very general agreement in describing the ordinary forms of 
pearls under various designations. The usual terms employed are round, button- 
shaped, and pear-shaped. Other descriptions are oval, half-round, biscuit- shaped, 
egg-shaped, etc. Many refer to rough and irregular pearls, while others omit these 
as having little or no value, and hence evidently not regarded as worth mentioning. 
Several speak of the spherical pearls as most valued, then the hemispherical, and then 
the oval. All this, of course, is familiar. 
In regard to color the answers are interesting, as showing the peculiar feature of 
Unio pearls — their wonderful variety of tint. Many papers merely say that they 
are of “all colors,” “various,” etc., but three-fourths of them, either under this head 
or the next, specify certain colors as most frequent, most prized, rare, etc. In 89 of 
