668 U. S. BUREAU OF FISHERIES 
drying pools and sloughs along the Mississippi, where they are left by high 
water, are inoculated with glochidia and released. However, there is no con- 
trol of these fish after they are released. We have no reason to believe that 
any very large proportion of the young mussels are dropped by their hosts in 
localities where they will survive, nor that they will escape their enemies, and 
passing destructive physical conditions during the first 10 days or 2 weeks 
of their free state—an extremely critical period in their life. However, button 
manufacturers and many others are convinced that the marked increase in 
abundance of the more valuable shells in certain areas is due to the bureau’s 
activity, 
The culture of mussels in troughs at Fairport has been going on for years 
in a small way by inoculating fish and permitting them to drop the young 
mussels in troughs, where they may be cared for through the first season of 
their growth. The number of glochidia that may be eared for by one fish is 
limited, however, making it quite an elaborate operation to obtain many mus- 
sels that way. Inoculating the maximum load of glochidia upon a fish also is 
a strain upon the fish. The mortality among the fish used in the trough 
culture of mussels has been heavy, and there is reason to believe that to a 
less extent it is heavy among the inoculated rescued fish also. 
Doctor Ellis’s work, at one stroke, does away with the necessity of inocu- 
lating rescued fish, and at the same time permits planting young mussels in 
large numbers upon mussel beds, where they may do best, and at an age when 
they have passed the early critical period. 
While Doctor Ellis is confident that the main work is done, it is necessary 
for him to develop a bactericide that may render glochidia free of bacteria when 
placed in the nutrient solution, but which will not injure the glochidia. It 
is necessary that the glochidia be sterile when placed in the solution, other- 
wise bacteria that may be present will increase sufficiently rapidly to destroy 
the glochidia before metamorphosis is quite complete. Doctor Ellis expects 
to complete this work this coming summer. 
Doctor Ellis also undertook for the bureau some work on the life history 
of the two species of gar found at Fairport, in connection with a study of the 
life history of the yellow sSandshell (the most valuable of all fresh-water 
mussel shells), which is parasitic upon the gar. Bearing in mind Doctor 
Hllis’s nutrient solution this fact may not be important, but for a better under- 
standing of the yellow sandshell it has seemed best to study the habits of 
the gars. 
Tie trough culture of mussels was continued at the station on a small scale 
during the past summer. Some new ideas were tried, which it is believed may 
be used to advantage in Doctor Ellis’s system as that is developed. The juve- 
nile mussels obtained were planted in certain Virginia waters by H. O. Hesen, 
who had charge of an investigation of the results of previous plantings of 
commercial mussels in these waters. No indications that these mussels were 
becoming established were obtained. 
As a result of correspondence between the bureau and the game and fish 
commission of Arkansas, a cooperative plan was made for a survey of the 
mussel-producing waters of Arkansas, with a view to working out a satisfac- 
tory open and closed system for areas of mussel waters. A previous system 
failed because the areas were too large. 
Ample proof had been obtained that Doctor Coker’s plan of dividing mussel 
waters into unit lengths and closing every other unit, with the understanding 
that at the end of given periods the open and closed sections should be alter- 
nated, was highly efficient for conserving mussel resources. Both the bureau 
and the commission, therefore, were anxious that a workable plan embodying 
these features should be put into effect in Arkansas. I was sent to Arkansas 
in May, and with members of the commission covered virtually all of the 
mussel waters of the State in about three months. Points that would serve 
as divisions between open and closed sections were studied carefully and a plan 
finally was worked out and presented to the commission. As recommended, the 
plan was first published in State newspapers and criticisms requested. As the 
result of suggestions some minor changes were made aud the plan goes into 
effect in February, 1927. 
The station has been making a series of surveys of certain mussel areas in 
the upper Mississippi waters, especially Lake Pepin, a widened portion of the 
Mississippi lying between Minnesota and Wisconsin. It was intended that 
these surveys should give an adequate idea of the extent of the mussel resources 
of these areas and indication of any trends in the supply. Up to the present 
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