American Fisheries Society. 241 
perimenter were not corrected for several months and various 
other difficulties were encountered which would now be foreseen 
and forestalled. Those which have suffered fewest vicissitudes 
showed a mortality of five per cent after eighteen months and 
ten to twelve per cent after thirty months. Though most of the 
lines showed a mortality far in excess of this, it is believed that 
with the experience now available and under the constant care 
which they should receive the mortality would not exceed fifteen 
per cent in three years and even this could undoubtedly be re- 
duced. The quality of the artificially grown sponges depends 
largely upon the environment under which they are grown, but 
in all cases it is superior to that of the natural sponges grown in 
the same locality. The texture is closer throughout, the surface 
is more closely felted, the shape is superior to that of the average 
natural sponge and there are no shells or rocks to be removed or 
clipping necessary to prepare the sponges for the market. One 
of the chief merits of the artificially grown sponge is that it has 
no “root” so-called. The root is that portion of the sponge which 
is attached. When it is torn loose, it leaves a raw surface which 
is the first part to wear out in use. In the artificially grown 
sponge, the whole surface is felted and equally durable, and 
ordinarily the orifice through which the wires pass will escape 
the closest examination. ‘The large specimen shown passed 
through many vicissitudes and the large size of the hole is due 
to the fact that it was loose on the wire and its rotation wore 
away the tissues. 
The sponges appear to be of better quality, so far as the char- 
acter of the surface is concerned, when harvested in winter. Most 
of the growth takes place in the summer and there is then a pre- 
ponderance in the production of the radial fibres, but during 
periods of slower growth, the production of tangential fibres fills 
in and felts the surface. 
Winter or late autumn and early spring are also the seasons 
for planting, as the cuttings can then be handled with less Habil- 
ity to injury. 
In conclusion, the statement should be emphasized that the 
experiments are not yet conclusive, that the Bureau of Fisheries 
is not yet prepared to recommend sponge culture as a practical 
industry and that the loss of some of the larger specimens during 
