564 BULLETIN OF THE BUREAU OF FISHERIES. 
cloth between the porcelain and the ribbon to prevent wear and tear on the 
lead covering of the latter. 
All of the foregoing experiments were made with a view to the utilization 
of soft muddy or grassy bottom upon which sponges will not grow naturally 
and in depths not exceeding 10 or 12 feet. This would have made possible the 
utilization of considerable areas among the keys and close to shore along the 
Gulf coast, in localities where the plantations could be readily protected. ‘The 
results of the work, however, have failed to disclose a material which is satis- 
factory in all respects. The lead-covered iron ribbon if carefully handled and 
planted with its casing uninjured has sufficient durability and prevents the 
loosening of the sponges as they reach commercial size, but it is not a com- 
mercial product and has to be made to order, which militates against its use 
by small planters, while its weight makes it somewhat difficult to handle in 
lengths of more than 15 feet, this, in its turn, increasing the cost of stakes, 
rings, and attachments. The rings and insulators will last indefinitely, the 
stakes will have to be renewed once during the growth of the sponges, and the 
indications are that the ribbon, or at least most of it, will not be useful for a 
second planting. Lead-incased galvanized-iron underwriters’ wire about one- 
fourth inch in external diameter with no. 12 Brown & Sharp gauge core is 
durable, costs about one-half as much as the ribbon, is easily handled, and 
much of it can be used for a second planting, but on account of its circular 
cross section the sponges as they grow will loosen and rotate in any but the 
most sheltered places. 
The value of a method which would permit of the utilization of otherwise 
useless and barren bottom in shoal water is great and warrants further experi- 
ment, but the results so far obtained are not such as would justify the recom- 
mendation of any of the methods or materials experimented with. The experi- 
mental results of the work with wires are valuable on account of the facility 
with which the sponges could be examined and the data which it has been 
possible to obtain as to the rate of growth, the mortality, and the general behavior 
of the cuttings. 
As has been mentioned, in the very beginning of the work experiments 
were made with various bottom attachments. The use of stakes or poles has 
already been discussed and the objections stated. They never offered much 
encouragement for further trial. The plaster, cement, and pottery forms first 
employed were about 5 inches in diameter on the bottom, 4 inches on top, and 
about 114 inches thick. The larger face was slightly convex, and the smaller, 
to which the cutting was attached by means of a V-shaped wire running through 
a central hole, was flat. They were found to be too small, tending to capsize 
as the sponges grew and offering greater surface to the impact of waves and 
currents, and there was also some difficulty with silt and vegetable growths which 
