SPONGE CULTURE. 599 
However it might be effected, this expense would have to be added to that 
involved in taking up the sponges with which to stock the parcs. It remains 
to be seen whether these expenditures would be covered or exceeded by the 
profit from this enterprise. 
Everything depends upon the rapidity of growth of the sponges. We have 
already noticed the data obtained. In Tunis, for example, we may expect from 
what we have learned that specimens of Hippospongia equina elastica, too 
small to be sold immediately, may be placed in pares and would be ready for 
preparation beginning with the following year. Profit would be rapidly obtained 
from the difference in price for small sponges, which must be sold at a loss, and 
that of sponges of commercial size. It is difficult to calculate, however, whether 
this difference in price would counterbalance the expenditures involved. This 
is a question to be solved by experience alone. So far, we have the right to 
have a limited confidence in the future of this method of culture, but not to 
believe in its importance, since it seems that it can never be adopted on a very 
large scale. 
SPONGE CULTURE BY MEANS OF COLLECTORS FOR LARVZE. 
This method, which might be considered as the most perfect theoretically, 
consists of parcage, not of the small sponges obtained by difficult and very 
expensive fishing, but very young sponges, fixed on adequate collectors. This 
method was neglected by most of the experimentors in spite of the advantages 
which it presents theoretically ; this comes from the fact that the authors hesitated 
to undertake observations on larve of sponges, the average length of which is 
of about half a millimeter. 
Ralph M. Monroe,‘ after having stated the results obtained by sponge 
culture by cuttings, says: 
It is quite possible that with state protection to the planters, and better methods 
to be determined upon by further experiments, sponge culture might be quite profitable. 
My belief is, gained in oyster culture from spawn, that a similar method with sponges 
will eventually prove the correct one, but until more is known of sponge biology it 
would be useless to suggest methods, notwithstanding the fact that several points in 
connection with it have been to my mind quite clearly demonstrated.” 
In “L’Industrie des Péches aux Colonies’’ we read: 
The desired aim might be more easily reached, perhaps, in operating on methods 
similar to oyster culture and clam culture, by receiving on suitable collectors the larve 
given out by sexually mature sponges in closed spaces. * * * It should not be 
forgotten, however, that it would be a very difficult attempt. 
@¥. V. Wilson has studied the reproduction of sponges ‘‘by means of eggs, by means of the gem- 
mules, and by cuttings.” (Report Commission of Fish and Fisheries 1889-91 (1893).) _Wilson’s works 
have been published, but he is not engaged in sponge culture. 
bIn Allen. 1896a. 
