314 
BUI-LETIN OF THE UNITED STATES FISH COMMISSION. 
in view of the desirability of redncing the fishing season as little as practicable. 
The measure, therefore, which would probably accomplish the most good would be the 
establishment of a close time for “ uiggerheads ” from January 1, or the time of ice 
formation in the Mississippi, to May 1. 
3. Provision should he made for the prevention of damage to the beds bg sewage and 
factory refuse. 
The damage to the mussel beds in the Mississippi Elver in Iowa and Illinois by 
river pollution is to a large extent prospective, but adequate steps should be promptly 
taken to obviate this source of injury. The effect on animal life — especially that on 
the bottom — of the discharge of city and factory refuse into streams has hardly been 
considered by those interested in the preservation of the mussels, but it constitutes, 
perhaps, the most serious menace to the industry, in that the destruction wrought is 
inevitable and complete. Mr. Simpson thus refers to the injury to mussels which is 
caused by antiquated methods of disposing of refuse: 
The dumpings of manufactories and the sewage of cities turned into rivers is destroying not 
only the fish but the Naiades. In many places below factories or cities the water of the streams is 
offensively foul and wholly changed in color, so that practiciilly no kind of organic life can exist in 
it. Along the Potomac and Shenandoah rivers, in the vicinity of Harpers Ferry and above it, are a 
number of mills which grind wood into a pulp for the manufacture of pai)er. These throw their 
sawdust and waste into the streams, and down below, where the water is comparativelj' quiet, it 
settles to the bottom, forming great masses of slushy, putrid matter, which is, no doubt, destructive 
to fish and unios. The city of Chicago is about to turn its sewage into the Des Plaines River, from 
which it will be carried into the Illinois River, a stream abounding with the very finest fresh water 
mussels. There can be but little doubt that this great volume of filth aud poison will destroy every 
Naiad in both of these streams, aud possibly it may exert its deleterious influence even on the 
Mississippi River also. 
4. In order that local industries may be fostered and the catch of mussels made no 
larger than can be utilized by the factories in the vicinity, the matter of prohibiting the 
shipment of shells to distant States .should be considered. 
There is little doubt that the button factories now in operation in Iowa and 
Illinois can more than consume all the mussels that should be gathered from the 
section of the river under discussion. It is held by some persons having pecuniary 
interests at stake that the raw materials should be reserved for those who have 
invested their caifital in permanent inqirovemeiits and have established local industries, 
and tliat the continuance of the business should not be endangered by unrestricted 
shipment of shells to distant States and countries. 
5. Button manufacturers should exercise greater care in utilizing their shells in order 
to reduce the ivaste of raw material. 
This subject has already been sufticiently- discussed. 
