PROJECTS FOR THE IMPROVEMENT OF SPONGE-FISHERIES. 199 



It must be remarked that it is difficult to see how any process of 

 culture can be possible, unless private property in areas of sponge-fishery 

 can be recognised and protected. [Cf. (1) (6)]. 



I see that Mr. Allen properly suggests the possibility that the deeper 

 waters of the Bahamas may with advantage be exploited. If this be 

 done, as in the Mediterranean, by divers without diving dresses, I would 

 suggest encouraging them to try the use of water-spectacles. I am not 

 aware that these have been ever used either for pearl-fishing or sponge- 

 fishing ; but, while every student knows that the imperfection of the 

 submerged human eye can be corrected by convex lenses, there is a 

 wide gulf of ignorance separating the student from the pearl-diver of 

 the Indian Ocean. Probably any wholesale optician would supply 

 spectacles of the required formula at the price of a few pence. The 

 experiment might be worth instituting at Ceylon. 



B. Transport of Sponges from the Mediterranean to the Bahamas. 



If it were desired to transport European sponges alive to the 

 Bahamas, I believe that this could be done. The sponge of commerce 

 lives well in the Naples Aquarium, and I see no reason why it should 

 not live in a suitably constructed tank on board a ship. In this way a 

 number of individuals might be transported, and deposited in a space 

 cleared from other sponges at a spot where the fishery is good, there to 

 breed as they successively ripened. If it were practical from the 

 nautical point of view, I should suggest the use of a closed wooden tank, 

 with perforated sides, flat bottom, and pointed ends, to be towed behind 

 the ship ; just floating enough to keep a flagstaff out of water in case of 

 accident. The sponges should be gathered with the pieces of rock to 

 which they adhere, and these stones fixed firmly in the bottom of the 

 tank. Before employing this method, it might be prudent to make 

 aquarium experiments as to how far the high surface temperature of 

 the seas traversed may prove deleterious to the sponges. Were such 

 temperatures proved to be fatal, it would be necessary to use an aquarium 

 inside the ship, artificially cooled.* 



* Since the text was in type, I have been able to consult Lamiral's original account (3) 

 of his unsuccessful attempt, iu 1862, to acclimatise Syrian sponctes on the French coast. 

 He placed 150 sponges in six cubical boxes of 2 ft. 7 in. each way, six similar boxes being 

 used for reservoirs to maintain a circulation (cooled with such ice as he could obtain), 

 and the whole carried on the deck of a crowded packet-boat. This apparatus was quite 

 inadequate ; and his description leaves little room for doubt that the tanks were lined with 

 bacterium slime from the very beginning of the voyage, and that the sponges hopefully 

 planted on the French shore were in various stages of putrescence. 



He records the bottom temperature at Tripoli in May as 19° C. in ten fathoms of water ; 

 his reservoirs on the journey rose to 23° C. and 2^>' C. An interesting account of tlio 

 Syrian divers is given ; besides useful details as to qualities of sponges, kc. 



NEW SERIKS— VOL. IV. NO. 2. ^ 



