590 . BULLETIN OF THE BUREAU OF FISHERIES. 
from one locality to another, either to increase the number of individuals in an 
already sponge-bearing region, to improve their production, or to make a barren 
region yield. It would be sponge culture to take young sponges from a natural 
bed and transplant them to a given area of the sea, a parc, where they might 
acquire a good commercial size under the supervision of a caretaker. - It would 
be sponge culture to gather sponge larve on appropriate collectors and rear them 
in a suitable place. It would be sponge culture to break a sponge in several 
pieces and develop separately the individual cuttings. 
It is thus possible for us to conceive various methods of sponge culture, each 
of which merits individual study, for we feel more or less strongly the lack of 
knowledge concerning the physiology of the sponge species when we take up the 
different methods. We shall call the first method sponge culture by sowing, 
the second sponge culture by parcage, then sponge culture by means of col- 
lectors, and lastly sponge culture by cuttings. 
GENERAL CONSIDERATIONS. 
The first question to be considered, as it belongs to all the methods, con- 
cerns the choice of the locality in which sponge culture is to be attempted. As 
a general rule, it is necessary to provide surroundings identical with those in 
which sponges naturally live as regards the depth and the quality of the water. 
It is, consequently, unnecessary to insist on the fact that the salinity of the 
water must be similar to that in which the sponges prefer to propagate; for 
example, care should be taken not to repeat the error of Lamiral, who 
attempted to introduce sponges from the Levant into the brackish ponds of 
the Mediterranean Sea. 
Delage said that the sponges of commerce require somewhat rough water, 
which keeps in suspension the grains of sand, the remnants of Foraminifera, and 
the spicules of sponges which accumulate in the primary fibers of their skeletons. 
This, however, is an exact theoretical consideration which may be entirely over- 
looked in practice. The entire volume of mineral débris which a toilet sponge 
keeps inclosed in its spongeous sheath is never very large; it does not exist 
near the coasts where sponge culture is possible; there are probably few locali- 
ties far from the coast where the purity of water is so great that sponges might 
suffer from a want of material for the formation of their skeletons. 
The authors reporting experiments in sponge culture almost all agree on 
one point, i. e., that the results of these experiments are always remarkable 
when made in waters where there exists a certain current. Buccich and 
O. Schmidt” advise localities but little exposed to waves coming in from the open 
sea, the bottom lined with highly cclored alga, and a certain current present. 
@J¥n Marenzeller. 
