798 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [46] 
bottoms which are naturally solid, and only altered by superficial de- 
posits. 
Muddy bottoms.—As is well known, mud is the result of the deposi- 
tion of pulverized material of any kind which is held in suspension 
by the water, having been gathered from the bottom of the open sea 
during stormy weather, or produced by the decomposition of animal 
and vegetable forms, or by the erosive action of the waves upon sub- 
marine rocks. So long as the water is in constant agitation these mate- 
rials remain in suspension, and no mud is deposited; but whenever 
the water becomes quiet, these fine particles, being denser than the 
water, drop to the bottom, resulting in the formation of mud; however . 
short a time the stagnation favorable to this deposit continues, so long 
as it lasts the layer of mud goes on increasing in thickness until the 
entire bottom is rendered completely sterile. The first thing to be done, 
then, in order to render a muddy bottom suitable for the growth of oys- 
ters, is not only to clear the bottom of the mud, but especially to pre- 
vent its future deposition. The most certain and most economical — 
method is to make the water itself remedy the evil which it has produced, 
and prevent its return. One very simple ‘observation will be a lesson in 
this direction. A deposit of mud is never found at the foot of a rocky 
cliff, or distributed over a bottom covered with reefs or ridges, since in 
such localities the water, even in the calmest seasons, is never in per- 
fect rest, but always in motion, and broken into thousands of little 
streamlets and currents by the many obstacles which it encounters. 
Although pure, the water of these sections is always charged with in- 
finitesimal particles taken from the mineral substances of the bottom, 
or ground up from the organic debris which is found here. These par- 
ticles can be recognized without trouble when the rays of the sun pen- 
etrate down into the water, just as in a chamber the particles of dust in 
the air mark the ray of light which penetrates the room. In a word, in 
sections of this character the water makes mud but does not deposit it. 
It is this natural effect which it is desirable to have produced artificially 
upon bottoms covered with mud, first to clear the mud away, and sec- 
ondly to prevent itsreturn. In order to accomplish this a wall of broken 
and irregular fragments of rocks so disposed as to produce the greatest 
number of obstacles and checks to the action of the waves is built along 
the edge of the shore, at the extreme inner limit of the mud. The next 
day the success of the movement becomes apparent, the sea comes 
rolling in and breaking against the rocks, lashing them upon all sides; 
it stirs up the mud from the bottom and retires loaded with the sedi- 
ment which it bears off with it, until all the mud along the base of the 
wallis gradually borne off to sea. A gain of ground having been thus 
accomplished, a second wall of breakers is formed outside of the first, 
and when the space in front of this is clear of mud, a third line is run 
around the second, and so on, breaker after breaker; by gradually driv- 
ing the mud farther and farther into the sea, solid and permanent 
