A PRACTICAL METHOD OF SPONGE CULTURE. 575 
It will be seen that at the end of four years the volume of 20 cuttings 
made from a 6-inch sponge will be over three times that which the same sponge 
entire would have attained under the same conditions, while 50 cuttings made 
Volume in 
cu. in. 
3000 50 pieces 
2800 
2400 
2000 20 pieces 
1600 
1209 
Ent're 
sponge 
No. of 
years after planting-.------_--_- I 2 3 4 
Fic.6.—Comparativeincreasecin volume of an entire sponge and of the aggregate of cuttings from sponges of equal volume. 
from a sponge of the same size will have a volume nearly 5 times as great. 
It should be explained, however, that these data do not represent a concrete 
case, but are based on observed rates of growth of cuttings and entire sponges 
under the same environment. The experiment begun to demonstrate these 
facts was interrupted by theft and vandalism. 
