288 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
below. It is not likely that pearl-liuuters or button-makers will ever completely exter- 
minate any of the species. There will always be some individuals left (especially 
where they are not abundant enough to make it pay to collect) to proj)agate the race. 
Fishes also can be depended on to carry the young about and plant them, thus form- 
ing new colonies and helj)ing to restock the old ones. But sewage and much of the 
refuse from manufactories will kill everything downstream. It is to be hoped that 
some plan may be devised to utilize this waste, otherwise it will be difficult to compel 
cities and mill-owners to dispose of it in any other way than by turning it into the 
water- courses. 
The immense number of mussels taken by iiearl-hunters and the manufacturers 
of buttons and ornaments, generally in the most wanton and wasteful way, is 
undoubtedly diminishing the supply with great rapidity. In cases where individuals 
are collecting independently, either for i^earls or to sell to manufacturers, it would 
probably be very difficult to get them to even throw the small mussels back into the 
water. But manufacturers, who ought to be intelligent enough to understand how 
rapidly the supply is becoming exhausted, and how much it is to their interest to pre- 
serve it, might at least use their influence to have those in their employ attend to this 
matter, and where corporations or individuals have control of water from which col- 
lecting is done they could comiiel attention to this. Ho mussel less than four or five 
years old should be taken by a iiearl-hunter or anyone engaged in collecting for a 
manufacturer. Such young specimens would not furnish pearls of any value, and, as 
a rule, they are too small to be used with profit for buttons. 
Certain regulations might be made in regard to dredging, raking up, and other- 
wise disturbing the beds of mussels. Mr. J. F. Boepple, president of the principal 
button factory at Muscatine, Iowa, who has given this subject much attention, 
believes that the disturbing of the beds at the time when the animals are loaded 
down with young is a cause of much injury, and he is no doubt right. When the gills 
are tilled with embryos they often protrude when the shell is open, and if disturbed 
they snddeidy close the shell, sometimes cutting ott‘ large portions of the ovisacs. 
It is doubtful whether any part of the year could be selected for a closed season 
that would be much better than another part. There is not enough yet known about 
this matter to give complete data to work upon, but from what I have seen in the 
examination of many thousands of animals taken throughout a wide range of country, 
and during the greater part of the year, and tlie statements of others, it would seem 
that the process of breeding is going on with some of the Naiades all the time. 
Sometliing, no doubt, might be done in the way of mussel farming, just as oyster- 
growing is made profitable. The great mussel shoals on the Tennessee Eiver, reaching 
from Fbu'euce, Ala., for 20 miles up the stream, are literally blocked with mussel shells. 
I have seen ripples in rivers where one could not step for a mile without treading on a 
living mussel. Such places, if kept under control and properly worked, ought to prove 
immensely profitable, and they need never be exhausted or even reduced. 
