SPONGES 



55 



Intl. d. UnioertOdt Gnu. (16) Id., "CTtaticnger" Report m the Calcarea, 1883. 

 (/7) Id., Ditto on the Ceratosa, 1884. (ig) Ridley, On Ou Zool. Collection of the 

 "Alert," 1884. (/o) Schmidt, Sponges of the Adriatic Sea, 1862, with Supple- 

 ment 1 in 1864, and Supplement 2 in 1 S06 ; Sponges of the Coast of Algiers, 1868; 

 Sponge-Fa-una of Ou Atlantic, 1870 ; Sponges of the Gulf of Mexico, 1879. (20) 

 F. E. Schulze, investigations into the structure and development of sponges, 

 in Ztschr. f. Kiss. Zool.," On Halisaraa," voL xxviii., 1877 ; " On Chondnsidx," 

 nil., 1877; "On Aplysinidtc," DOL, 1878; "On Metamorphosis of Sycandra 

 raphanus," ixxi., 1S7S; "On Spongdia," xxxii., 1878; "On Spongidx," ib. ; 

 "On Hircinia and Oligoceras," xiniL, 1879; "On Plakinida," ixiiv., 1880; 

 "On Corticium candelabrum," mv., 1881. (*/) Id., "On Soft Parts of 

 Euplectella. aspergillum," in Trans. Boy. Sac. Edin., xxix., 1880. (.?->) Id., 

 Preliminary Report on the "Challenger" Heiactinellida. (23) Id., "On the 

 Relationship of the Sponges to the ChoanoJIagellata," in SUz.-Ber. d. k.-preuss. 



the Triininingham Chalk," i*., vL, 1879. (*7) Id., " Development of Halisarca 

 tobularis," in Quart. Jour*. Micr. Sci., nriv., 1884. (28) Id., " On Vetulina and 

 the Anomadadina," in Proe. R. Irish Acad., iv., 1885. (19) Id., "Physical 

 Characters of Sponge-Spienles," in Proc. R. Dub. Soc., 1885. 'jo) Vejdovsky, 

 " The Freshwater Sponges of Bohemia," in Abk. d. k. Bdhm. Akad, d. Wiss.. ser. 

 Ti., voL ni., 1883. (31) Vosmaer, OTI Leucandra aspera (doctor's diss., Leyden, 

 1SSO). (32) Id., "On the Desmacidinid*;," in Sates from Ou Leyden Museum, 

 vol. ii. (S3) Sponges of the H'illem Barents Expedition, 1884. (?*) " Poriferse," in 

 Bronn's Klasstn und Ordnungen, vol. ii., 1882, and still in progress, (jy) Zittel, 

 studies of fossil sponges, in Abh. d. k. buyer. Akad.,-Hetactinellida, 1877; 

 Li&istida, 1878 ; Monactintllida and Calcarea, 1878. 



Commerce. 



When the living matter is removed from a Ceratose 

 sponge a network of elastic horny fibres, the skeleton of 

 the animal, remains behind. This is the sponge of com- 

 merce. Of such sponges the softest, finest in texture, and 

 most valued is the Turkey or Levant sponge, Euspongia 

 ojfirinalis, Lin. The other two varieties are the Hippo- 

 fpongia equina, O. Schmidt, and the Zimocca sponge, 

 Euspongia zimocca, O.S., which is not so soft as the others 

 Distribu- (see p. 423 above). All three species are found at from 2 

 tion. to 100 fathoms along the whole Mediterranean coast, includ- 

 ing its bays, gulfs, and islands, except the western half of 

 its northern shores as far as Venice and the Balearic Isles, 

 Corsica, Sardinia, and Sicily. Bath sponges occur around 

 the shores of the Bahamas, and less abundantly on the north 

 coast of Cuba. They are of several kinds, one not dis- 

 tinguishable from the fine Levant sponge ; others, the 

 "yellow" and "hardhead" varieties, resemble the Zimocca 

 sponge ; and of horse sponges there appear to be several 

 varieties, such as the " lamb's-wool " and the "velvet" 

 sponge (Hippospongia gossypina. and H. meandriformis). 

 The fine bath sponge occurs on the shores of Australia 

 (Torres Straits, the west coast, and Port Phillip on the 

 south coast). A sponge eminently adapted for bathing 

 purposes (Coscinoderma lanuginosum, Crtr. ; Euspongia 

 mathewsii, Lfd.), but not yet brought into the market, 

 occurs about the South Caroline Islands, where it is actu- 

 ally in use, and at Port Phillip in Australia. The fine 

 bath sponge occurs in the North Pacific, South Atlantic, 

 and Indian Oceans, so that its distribution is world-wide. 

 Fishing. The methods employed to get sponges from the bottom 

 of the sea, where they grow attached to rocks, stones, and 

 other objects, depend on the depths from which they are 

 to be brought. In comparatively shallow water they may 

 be loosened and hooked up by a harpoon ; at greater 

 depths, down to 30 or 40 fathoms, they are dived for; and 

 at depths of from 50 to 100 fathoms they are dredged 

 with a net. The method of harpooning was the earliest 

 practised, and is still carried on in probably its most 

 primitive form by the Dalmatian fishermen. Small boats 

 are used, manned by a single harpooner with a boy to 

 steer ; when, however, the expedition is to extend over 

 night the crew is doubled. The harpoon is a five-pronged 

 fork with a long wooden handle, and if this is not long 

 enough another harpoon is lashed on to it. The Greek 

 fishers use a large boat furnished with two or three smaller 

 ones, from which the actual harpooning is carried on ; the 

 crew numbers seven or eight. One of the chief difficulties 

 is to see the bottom distinctly through a troubled surface. 

 The Dalmatian fishers throw a smooth stone dipped in oil 



a yard or so in front of the boat ; the stone scatters drops 

 of oil as it flies and so makes a smooth track for the " look- 

 out." The Greeks use a zinc-plate cylinder about 1 J feet 

 long and 1 foot wide, closed at the lower end by a plate of 

 glass, which is immersed below the surface of the sea ; on 

 looking through this the bottom may be clearly seen even 

 in 30 fathoms. This plan is also adopted in the Bahamas, 

 where harpooning carried on after the Greek system gives 

 employment to over 5000 men and boys. 



The primitive method of diving with no other apparatus 

 than a slab of stone to serve as a sinker and a cord to 

 communicate with the surface is still practised in the 

 Mediterranean. The diver carries a net round his neck 

 to hold the sponges. On reaching the bottom he hastily 

 snatches up whatever sponge he sees. After staying down 

 as long as he is able an interval which varies from two 

 to at the most three minutes he tugs violently at the 

 cord and is rapidly drawn up. On entering the boat from 

 depths of 25 fathoms he quickly recovers from the effects 

 of his plunge after a few powerful respirations ; but after 

 working at depths of 30 to 40 fathoms or more he reaches 

 the surface in a swooning state. At the beginning of the 

 season blood usually flows from the mouth and nose after a 

 descent ; this is regarded as a symptom of good condition ; 

 should it be wanting the diver will scarcely venture a second 

 plunge for the rest of the season. The work is severe, and 

 frequently the diver returns empty-handed to the boat. 

 Diving is usually carried on in the summer months; in 

 winter it is too cold, at all events without a diving-dress. 

 The ordinary diver's dress with pumping apparatus is 

 largely used by the Greeks. The diving is carried on 

 from a ship manned by eight or nine men, including one, 

 or rarely two, divers. At a depth of from 10 to 15 fathoms 

 the diver can remain under for an hour, at greater depths 

 up to 20 fathoms only a few minutes ; the consequences of 

 a longer stay are palsy of the lower extremities, stricture, 

 and other complaints. Dredging is chiefly carried on along 

 the west coast of Asia Minor, principally in winter after 

 the autumn storms have torn up the seaweeds covering 

 the bottom. The mouth of the dredge is 6 yards wide 

 and 1 yard high ; the net is made of camel-hair cords of 

 the thickness of a finger, with meshes 4 inches square. It 

 is drawn along the bottom by a tow-line attached to the 

 bowsprit of a sailing vessel or hauled in from the shore. 



Prompted by a suggestion made by Oscar Schmidt, that Cnltiva- 

 sponges might be artificially propagated from cuttings, 

 the Italian Government supplied funds for experiments to 

 determine the feasibility of cultivating sponges as an in- 

 dustrial pursuit. A station was established on the island 

 of Lesina, off the Dalmatian coast, and experiments were 

 carried on there for six years (1867-72) under the super- 

 intendence of Von Buceich. The results were on the whole 

 successful, but all expectations of creating a new source 

 of income for the sponge-fishers of Dalmatia were defeated 

 by the hostility of the fishers themselves. 



The details of the method of sponge-farming as practised 

 by Von Buceich are briefly as follows. The selected speci- 

 mens, which should be obtained in as uninjured a state as 

 possible, are placed on a board moistened with sea water 

 and cut with a knife or fine saw into pieces about 1 inch 

 square, care being taken to preserve the outer skin as in- 

 tact as possible. The operation is best performed in winter, 

 as exposure to the air is then far less fatal than in summer. 

 The sponge cuttings are then trepanned and skewered on 

 bamboo rods ; the rods, each bearing three cuttings, are 

 secured in an upright position between two parallel boards, 

 which are then sunk to the bottom of the sea and weighted 

 with stones. In choosing a spot for the sponge-farm the 

 mouths of rivers and proximity to submarine springs must 

 be avoided ; mud in this case, as in that of reef-building 



