A PRACTICAL METHOD OF *SPONGE CULTURE. 559 
ATTACHMENTS. 
The chief problem confronting the experimenter in sponge culture is to 
find some ready and economical means of attaching the cuttings to a durable 
support which shall be capable of resisting the chemical action of sea water 
and the ravages of the teredo and other animals having similar destructive 
habits, and which at the same time is without injurious effect upon the 
sponges. During the course of the present experiments numerous materials 
and methods were employed, most of which sooner or later demonstrated their 
unfitness to fill the requirements. It was found that the cuttings would speedily 
attach to any firm, clean, innocuous material, and many methods of attach- 
ment appeared satisfactory for a year or two, but then developed some defect 
due to corrosion, tensile weakness, or the lack of sufficient attaching surface. 
It was necessary to await developments before the direction of further ex- 
periments was indicated, and much time was expended on materials which 
afterwards developed unexpected defects. 
During the first season the cuttings were attached to stakes and rectangular 
frames laid on the bottom, to vertical stakes, and to pieces of coral rock and 
small copper wires laid on the bottom. Some of the sponges were threaded on 
the supporting copper wires and others were bound to them by means of short 
pieces of lighter wire, with the expectation that the sponge would eventually 
encompass its support. About six weeks after the plants were made it was 
found that 95 per cent had healed and were living under apparently healthy 
conditions, but seven or eight months later most of them had died. It was 
expected that the action of the sea water on the copper wires would produce 
poisonous salts, but in quantities so small as to have merely a local effect. 
It was found, however, that wires one-sixteenth inch in diameter were com- 
pletely corroded away in places, especially where the cuttings were attached, 
and the latter were either killed, or lost by the breaking of the wires. The 
effects were especially pronounced when the wires were lying on the bottom. 
The cuttings placed on the bottom on rocks and stakes soon became covered 
with silt and vegetable growths and were either killed or lost, and it was evident 
that the choice of both materials and localities had been unfortunate. 
During the winter of 1901-2 advantage was taken of the experience gained 
during the preceding year, and in addition to Biscayne Bay and Sugar Loaf 
Key, where the first year’s experiments were made, Anclote Key was selected 
as an additional locality. Instead of using naked copper wires, various types 
of insulation were tried, other metals, including lead and heavily galvanized 
iron, and various cordage materials were experimented with, and molded forms 
of terra cotta, plaster, and cement were used in place of the rocks and stakes 
placed on the bottom. The more or less expensive insulations composed of 
