244 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



(Mulleria), so common in parts of the Bahama Islands. It was with the greatest 

 difficulty that a few embryos of this form could be got in the laboratory. When, how- 

 ever, the animals were confined in a large box anchored in about a fathom of water, 

 quantities of developing eggs could be had by drawing up with a tube some of the 

 sediment in the bottom of the box. 



The "spat" once obtained in abundance, success will next depend largely on the 

 selection of the locality in which the young sponges are to be set out. A careful study 

 of the Florida grounds should be undertaken, with the view of investigating, among 

 other points, this very matter of the kinds of locality best adapted to the growth 

 of the various grades of sponges. Quiet water, a firm bottom, and an absence of 

 muddy sediment seem essential desiderata. The question of enemies is probably 

 of minor importance, and yet the well-known student of sponges, Vosmaer, mentions 

 that he has several times seen the European hermit-crab (Pagurus) greedily eat a 

 common silicious sponge (Suberites), certainly quite as unappetizing a morsel as 

 the coarsest commercial sponge. 



When it has once been accurately determined what are the physicial and biolog- 

 ical characteristics of the Florida grounds, which produce the finest sponges and it 

 may be mentioned here that sponges are among the most variable of animals and 

 seem to be peculiarly affected by their surroundings a detailed comparison should 

 be made between these grounds and those parts of the Mediterranean producing the 

 finest grades. The purpose of such a comparison would be to discover whether we 

 really lack any of the natural advantages necessary for the production of the finest 

 sponges and, if so, whether these can be artificially reproduced whether, for instance, 

 it would be possible or desirable to imitate on this side a particular kind of bottom 

 found in the Mediterranean. 



Following on the investigation of the sponge- grounds, I believe it to be eminently 

 desirable to start a series of experiments, the purpose of which shall be to discover 

 how far, along what lines, and by what means sponges may be artificially altered by 

 breeding. The great variability of sponges in nature leads one to believe that they 

 would quickly respond as individuals to a change in the environment, and thus, simply 

 by growing the animals in a superior locality, an improved variety, constant, as long 

 as the sponges continue to grow in that locality, might be produced. It is quite 

 likely that such improvements could be carried out on sponges propagated by cuttings 

 as well as on those grown from eggs. In improving races, however, it has always 

 been found that the two important means are sexual breeding from selected specimens 

 and. grafting, the latter method being commonly regarded as only applicable to plants. 



In sponges, as in other organisms, increase of knowledge will in all probability 

 confirm the belief, already fairly well grounded, that individuals developed from the 

 fertilized eggs vary more, i. e., exhibit more differences one from the other, than indi- 

 viduals grown from buds or cuttings. Herein, to my mind, lies the advisability of 

 growing sponges from eggs as well as from cuttings. The latter method, being quick, 

 sure, and simple, can at once be made of great practical use. Breeding from the egg 

 is more complex, and must be carefully tried by competent experimenters. In the 

 end, however, I believe that it will lead to great improvements in the quality of our 

 sponges. 



I would suggest that, after selection of a proper locality, a small plantation of 

 sponges developed from eggs be started and carefully watched. As the sponges grow, 

 it would be a simple matter to pick out those individuals in which the fiber varied in 



