420 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
become exhausted yearly arid re-becl in one or two years; still another (Tennessee) 
states that the shells return every year, but in less numbers; and one (Texas) reports 
that many beds that had been worked out are recovering, through the growth of the 
young shells that were left unmolested. 
The twenty-ninth inquiry, as to whether exhausted beds recover and in what 
time, is closely connected with the preceding one. It is unanswered in 25 of the papers 
and 9 others report no knowledge or opinion on the subject. Eighty-eight replies 
are given, of which several are indefinite and conjectural. Out of about 80 papers, 
therefore, or two thirds of the whole, 26 report the belief that the beds are replen- 
ished from year to year; 8 in one or two years; 4 in two or three years, and 4 in 
four years; 6 name periods between four and eight years and 7 between eight and 
twelve years; 1 gives twenty years;- 1 gives twenty-five, and 2 estimate the recovery 
as requiring a century or more; 4 papers say that many years are necessary; 6 say 
u a few” or ‘‘soon”; 4 report no exhaustion as noticed, aud 6 report no recovery. 
Several papers are indefinite or uncertain. Two of those that give estimated dates 
for recovery do so with an expression of doubt (“if at all,” “if ever”) as to wdiether it 
really occurs. A Tennessee paper says that the shells return each year, but in less 
numbers. As it is customary, more or less, to leave the young and small shells, the 
question resolves itself largely into two, viz, how far they have been carefully spared 
and how long it takes them to attain their growth. This last probably differs iu 
different species, as is intimated in some of the answers, and it may also be influenced 
by various external conditions. Another Tennessee paper estimates the recovery as 
slow, from the fact, previously brought out very markedly, that the young shells are 
those that are most exposed to all natural enemies and accidents. A New York 
paper, which thinks that there is no recovery, states that few young shells are found. 
A Texas paper says that young shells are found in two years, but contain no pearls, 
and another from the same State says that many beds are recovering by the growth 
of the young that were left before. On the other hand an Indiana paper states that 
when a bed has been worked out plenty are found the next season, and an Iowa paper 
reports young shells abundant everywhere. One of the papers from Tennessee probably 
gives a very fair average statement, to the effect that the beds recover somewhat 
every season, and would, perhaps, recover entirely in a few years, if not molested. 
The concluding inquiry, as to whether State protection of the beds is desirable or 
necessary, is answered with more or less definiteness in 97 papers, and, as might be 
expected on such a subject, with much diversity. Fifty-nine of the responses see no 
need or advantage from protection and 33 favor it. One or two fail to understand 
the purport of the question clearly, and some hold that while not necessary now it 
may be so in the future. Two or three say that it would be difficult or impracticable. 
A few of the answers may be referred to more particularly. Of those that do not 
favor protection, 2 (Michigan and New York) think it not worth while or desirable 
to preserve the Unios, the latter curiously remarking that “the water would be purer 
without them.” One Tennessee writer seems to hold a similar view, saying that 
protection is not desirable, though it is necessary to the preservation of the shells; 
another, failing to appreciate the question involved, opposes protection “ because pearls 
bring in a great deal of money, aud the mussels are of no use.” Two or three think 
that the shells are inexhaustible and in no danger of extinction. Of those that favor 
the suggestion, 1 from Indiana states that it would be well if no shells were taken 
for five years; the Ohio paper advocates it “if the mussels are to be preserved.” One 
