570 BULLETIN OF THE BUREAU OF FISHERIES. 
My own experiments show that the raw surfaces of cuttings become pig- 
mented within a few days and that at the end of a month they have completely 
healed and have begun to grow and project little papillae or cones. Sharp angles 
and edges generally die and slough off slightly, and the central portions of the 
plane faces become swollen so that at the end of three months in small cuttings 
and somewhat later in larger ones there is evident a distinct tendency to ro- 
tundity. At the end of six months in many specimens the cut faces can not 
be distinguished from the original surface of the sponge and in practically none 
can they be determined except by the shape. In all cases there is a constant 
tendency toward a spheroidal or ellipsoidal shape, cubical cuttings approaching 
the former and irregular ones the latter form if suspended above the bottom, 
but all becoming cake-shaped if grown from basal attachments. (Compare 
plates Lxxiv and Lxxv.) 
Growth takes place in all directions with approximate equality when the 
cuttings are suspended freely in the water, but is generally more rapid in the 
horizontal plane when the sponge is attached to a basal support. If the cutting 
be attached to a small horizontal surface it will grow downward over the edges, 
and if the surface be uneven it will project itself into all the irregularities and 
holes. For this reason, if basal attachments are used, it is desirable to have them 
with smooth surfaces and of a horizontal expanse greater than that of the sponges 
which it is desired to grow, otherwise considerable weight, and also time, is 
lost in trimming the marketable specimens to a desirable and uniform shape. 
Buccich observed considerable variation in the rate of growth and my own 
experiments confirm his statements. Cuttings which, so far as could be deter- 
mined, were similar in size, shape, and character, diverged widely from one 
another in this respect and some of them, while healing completely and remain- 
ing in an apparently healthy state, had grown hardly at all in the course of 
several years. In some cases cuttings made from the same sponge exhibited 
this diversity. Different lots of cuttings of the same average size and planted 
in the same locality exhibited a remarkably uniform average rate of growth year 
after year. In Sugar Loaf Sound the average annual increase in diameter was 
about 0.8 inch, while at Anclote Keys and Cape Florida it was from 1 to 1.2 
inches. In Sugar Loaf Sound this average was maintained to the end of three 
years, when the experiment was abandoned for reasons already explained, 
while at the other two places it continued until the end of four years, when accu- 
rate records were lost as the result of disasters due to meteorological causes. 
Recent developments in Biscayne Bay indicate that the average growth of 
sponges planted on the bottom in Cape Florida Channel is slightly in excess of the 
rate stated above, while at Soldier Key, about 7 miles away, it is much less. At 
the first locality the currents are strong, the bottom muddy, and the neighboring 
