THE OYSTER. 209 
The green molecules are arrested by the branchiz, and thus the 
action of the organ is much impeded. The poor animal, injured 
in one of its essential parts, seems to dilate and become more 
tender, and for this—its misfortune—is the more relished. 
The chief oyster farm in England is carried on by a joint- 
stock company, at Whitstable. The extent of the farm is about 
one and a half square miles. The beds of oysters are arranged 
along the shores of the estuary which separates the Isle of Sheppy 
from the main-land. “Natives” are oysters which are produced 
from these farms; those which are taken from their own beds out 
at sea are called “ Commons.” : 
Yet, in spite of the seeming power of cultivating the oyster 
ad libitum, the mollusk is decreasing in numbers, and consequently 
becoming dearer. The reason for this is not clear; one set of 
naturalists blaming the weather, another the currents, while most 
probably the true cause will be found to be the combined influence 
of the two; together with the natural desire to supply an increased 
demand which the rapidity of transit creates, at the expense of 
dredging the beds before they have recovered from their last 
thinning. The most evident way of obviating at least two of 
these difficulties is, to have parks after the French system, which 
are exposed at low tide. 
