MISCELLANEOUS NOTES. 
813 
No. XVIII.— PEARL BEARING IVIUSSELS. 
Mr. Laird Macgregor recently forwarded the Society a small packet of Pearls 
produced by a species of Mussel foxmd in a tank at Badas a few miles from Bel- 
gaum. Two examples of the Mussel were sent with the packet. Mr. Laii’d Mac- 
gregor wrote : — “ I do not suppose the pearls are of any value, but is it not 
rather unusual to find pearl bearing mussels in fresh water? ” 
The mussels and pearls were sent to Mr. Hornell, Director of Fisheries, Madras, 
for investigation and Mr. Hornell has sent in the following interesting re- 
marks in connection with them. 
“ The shells are of the common fresh- water mussel, probably Lamdlidens mar- 
ginalis. This species is often very abundant in fresh waterponds and streams 
and it is not uncommon for it to produce pearls. The quality is usually poor on 
accormt of the small size, poor lustre and frequent colouration. But when the 
mussels occur in large numbers and when they produce pearls freely, their collec- 
tion is remunerative ; such small pearls should fetch about Rs. 10 per tola 
weight and there is always the chance of finding a large pearl of fair lustre that 
may command a price of anything up to Rs. 50 or possibly even more. At 
Surada in Ganjam, fresh water Mussels producing pearls are so abundant that 
the villagers collect them for this pmpose and their pearls are often to be had 
in the village bazaars. Similarly in Bengal there is a well-known Zemindari 
fishery for these Mussels farmed out, I beheve, by the Zamindar for a considera- 
ble sum. 
Curiously enough these Mussels vary greatly in their pearl-producing quahty. 
In some localities, pearls are so seldom formed that collection of the Mussels 
is wholly unremunerative. This is due to the fact that the formation of pearls 
in these animals is due mainly to the presence of certain parasites. If these be 
absent, as in most localities, the Mussels produce few or no pearls ; if they be 
numerous, we may then expect pearl production to be abundant. 
The famous Scots pearls celebrated in the middle ages are produced by river- 
mussels closely related to those sent to me. As is well known these pearls are 
occasionally of considerable value. But they are distinguished by a pink 
tint which diminishes their market value. Those sent from Belgaum are simi- 
larly tinted. Several of these fresh-water pearl fisheries are still worked in the 
north of Scotland. Some Welsh streams also produce pearl-bearing Mussels. 
In North American rivers, the fishery for fresh-water mussels is a big industry 
emplojing hundreds of workers and a large capital. But while pearls are 
occasionally found of some considerable value, this fishery is conducted prima- 
rily to obtain mother-of-pearl for the pearl button factories. These consume 
many tons of these fresh-water Mussel shells. 
In India, this same industry has arisen in Bengal, where supplies of a species 
of Lamellidens are found in the rivers, sufficiently stout to permit of poor quality 
shirt-buttons being cut from the shell. I believe it might be worth while to ex- 
amine the streams and large tanks throughout the Bombay Presidency in order 
to ascertain if any species exists here with shell sufficiently thick and in good 
abundance, for if there be, then further quantities might be cultivated and 
the material sold for button making. 
Streams draining from or passing through a limestone region are the most 
likely to produce thick-shelled Mussels. Here in Madras, the streams are 
generally deficient in carbonate of lime and so our Mussels are almost wholly 
too thin shelled to be utilizable commercially.” 
