an absolute proof that the shells grow from within and not from the outside, as has sometimes been maintained.
It
is difficult to state anything definite as to the rate of growth of the
Mother-of-Pearl shell, but a case that occured in 1883 may be worth
mentioning as it excited considerable interest in the West Australian
fleet,
In
February 1883, the "Louisa," a cutter of 28 tons, was beached on the
Lacepede islands and her copper was thoroughly scrubbed and cleaned.
After remaining pearling during March, she was taken into a creek in
Roebuck Bay to clean and paint up for returning to Cosiack, the season
being over. When the ebb tide left her high and dry, it was found that
her bottom was covered in many places with small Mother-of-Pearl
oysters, from 1-1/2 to 3 inches wide ; one solitary shell
however measuring 5-1/2 inches across. The only feasible explanation of
this seems to be that these small shells were originally in the dirt
and scrapings of the shells which were thrown overboard the evening
after the copper was cleaned in February : this was before the vessel
was floated. The tide must then have washed them against the bottom, to
which they adhered. Considering, therefore, that they were found only
six weeks after the cutter's
