A PRACTICAL METHOD OF SPONGE CULTURE. 567 
on the under side (pl. yxvin, fig. 2). This is arather slow process, and it is not 
possible for two men to cut, attach, and plant more than about 100 cuttings per 
hour. ‘To accelerate the speed of planting I have placed in the center of each 
disk a short spindle of 14-inch lead wire, slightly flattened at the top by a blow 
from a hammer and projecting to a length of about 214 inches (pl. xvi, fig. 1). 
About 8 or 10 cuttings are placed on a long needle (fig. 3) of the required 
shape, the socket of which is placed upon spindle after spindle in succession and 
the cuttings pushed into place in contact with the 
cement base, each with a single motion of the left 
hand. Friction of the slightly stretched tissues 
against the spindle and the burr at the top of the 
latter prevent the detachment of the cutting, which 
in a few days grows fast to both the spindle and the 
disk. With this device two men can plant from 250 
to 300 cuttings per hour, and this gain in speed over 
the other method is highly important in places where 
rough weather is prevalent, as it makes possible the 
fullest utilization of such opportunities as present 
themselves. The spindles add about 25 per cent to 
the cost of the plain disks, but as they will survive 
a number of plantings this cost is compensated for 
by the decreased cost of labor. 
This system also facilitates replanting with cut- 
tings at the time of harvesting of the first crop, as 
the grown sponges can be quickly detached and 
new cuttings substituted. In shoal water where the 
sponges can be taken with hooks, two additional men 
in the boat should be ample to detach the sponges 
and replant the disks as rapidly as they are brought 
up. In deep water where a diver has to be em- 
ployed for harvesting the crop, the cuttings can be —) O 
taken down by the diver and planted as the matured ric. 3.—Needles used for threading 
sponges are removed, avoiding the labor and incon- pe 8 ae ae 
venience of bringing the disks to the surface, and reducing the cost of opera- 
tion very much more than sufficient to cover the increased first cost of the 
disks. 
The expense of labor in deep-water planting is of such importance that the 
strictest economy of operation, especially in taking up the sponges, must be 
given careful consideration. The diver’s time must be economized, as the 
time of the entire crew of the diving boat is dependent upon the rapidity and 
