554 BULLETIN OF THE BUREAU OF FISHERIES. 
the direction of its growth, although the character of one or both may be affected 
by any change in environment. A cutting from a sponge transplanted and 
grafted on another growing in a different environment will tend to approach 
the latter in character, not as the result of the graft, but on account of the 
physical surroundings, precisely as it will do if transplanted to the same locality 
without grafting. In other words, nothing can be done by grafting that can 
not be more readily done by propagation from cuttings which attach themselves, 
and the former process results in a waste of time and effort without compen- 
sating advantages. Neither cutting is improved by the amalgamation. Sponges 
of the same species will unite if grafted. Sheepswool sponges from different 
localities readily fuse, but they will not unite to either yellow or grass sponges, 
and probably not to any species other than their own. 
GROWING FROM EGGS. 
That sponges can be grown from eggs to a marketable size under the 
control which is essential to any system of sponge culture appears probable, 
but it has not yet been demonstrated. Although experiments made with the 
noncommercial sponges show that they can be kept alive for a considerable 
time after development from the egg, I know of no cases in which they have 
been artificially raised to maturity or to any considerable size, and experiments 
with the commercial sponges are still less conclusive. Raising sponges from 
the egg must probably always remain a delicate operation, practicable only to 
skilled investigators provided with special facilities and entirely beyond the 
reach of the practical man engaged in a commercial enterprise... For that 
reason the method appeared to be ill-adapted to the present needs of the sponge 
fishery and was therefore discarded in the experimental work described in the 
present paper. As has been pointed out, however, in an academic discussion 
of the proposition by H. V. Wilson, it may be that this method will have a 
distinct place in the sponge culture of the future, though its development and 
practice must probably necessarily be in the hands of a few skilled operators. 
It may be possible to breed sponges from selected parents, thus improving 
their quality and supplying better seed sponges from which to make cuttings. 
Possibly some system of hybridization may be developed along lines analogous 
to those which have produced such astounding results in the hands of experi- 
mental horticulturists. 
The plasticity of sponges and their extreme susceptibility to environmental 
influence, as well as the technical difficulties which the experimenter must over- 
come in his attempts at breeding and hybridization, will probably long postpone, 
if they do not entirely defeat, successful efforts in this direction. The problem 
is one which may well be taken up and studied when the Bureau of Fisheries 
comes into possession of a properly equipped laboratory in the sponge region 
of Florida. 
