146 



KNOWLEDGE 



[July 1, 1899. 



is brought to the surface is to remove the sarcode, or 

 flesh, as otherwise putrefaction speedily sets in and destroys 

 the elastic nature of the spongin. This preliminary 

 cleansing process is carried out at the gathering grounds, 

 in some cases even before the vessels reach the shore. 

 Sponges in this condition are commercially spoken of as 

 "raw," and have to undergo a further cleansing process 

 before they are suitable for use. How far this cleansing, 

 or bleaching, process is carried depends on circumstances. 

 When carried to its fullest extent, the sponge (as we may 

 now call the cleaned skeleton) becomes of a beautiful 

 lemon-yellow tint, and is known in the trade as " bleached " ; 

 on the other band, when this process is carried out only 

 to a limited degree and a more or less decided brown tint 

 remains, the sponge is said to be " unbleached." In all 

 oases, however, bleaching of some kind has been resorted 

 to— a raw sponge being unusable. 



The various descriptions of commercial sponges grow 

 at all depths between two and one hundred fathoms, in 

 seas where the temperature and other conditions are 

 suitable. The finest descriptions and largest quantities 

 are yielded by the Mediterranean, the chief grounds being 

 off the Greek and Turkish islands, thence through the 

 Dardanelles to the Sea of Marmora, and so along the 

 coast of Asiatic Turkey and Syria to Cyprus. From there 

 the Egyptian coasts may be followed, and thence westwards, 

 with some local exceptions, sponges may be traced along 

 the coasts of Tripoli and Tunisia nearly to Algeria. The 

 Spanish, French and Italian coasts are, indeed, devoid of 

 sponges, although they occur on the Turkish shore of the 

 Adriatic. The very best descriptions, such as the cup- 

 shaped toilet-sponge, are, however, met with only to the 

 west of Malta ; and as the Algerian coast is approached 

 the sponges become gradually coarser. 



Large quantities of sponges are met with off the West 

 Indian Islands, whence the banks extend to the coasts of 

 Florida, Mexico, and British Honduras. All these West 

 Indian sponges, as they are collectively called in the trade, 

 are, however, coarser, and therefore cheaper, than their 

 Mediterranean representatives. Commercial sponges also 

 occur in the Red Sea, the Indian Ocean, and on the 

 Australian coasts, especially on the Great Barrier Eeef. 

 Hitherto, however, none of these have been regarded by 

 the trade as of sufficiently good quality to repay the cost 

 of gathering. Owing to the constant drain upon it, the 

 sponge-fishery on the old grounds is becoming rapidly 

 exhausted ; and prices have for the last few years been 

 advancing by leaps and bounds. The ordinary depths for 

 fishing vary between fifteen and twenty fathoms, but of 

 recent years sponges have been gathered off Malta at a 

 depth of thirty fathoms. And it is hoped that the possi- 

 bility of fishing at still greater depths may before long lead 

 to the introduction of a large fresh supply of this invaluable 

 article. By the adoption of a specially heavy diving dress, 

 so constructed as to resist the terrible effects of pressure at 

 such a depth, it is confidently expected that collecting in 

 forty fathoms of water may ere long be found practicable. 

 In the Mediterranean sponges are chiefly gathered by divers 

 (either with or without the aid of the diving apparatus), 

 but trawl-nets and the harpoon are also largely employed. 

 Trawling, however, produces only damaged and inferior 

 samples, while even harpooning does considerable harm. 

 All Transatlantic sponges grow in shallower water, and are 

 therefore more easily fished than the Mediterranean ; and 

 this is doubtless one, though not the sole reason, of their 

 coarser structure. Except in British Honduras, Trans- 

 atlantic sponges are collected only by means of the harpoon. 

 An exhausted sponge-ground may be profitably reworked 

 p,fter an interval of four years, that period being sufiScient 



to allow sponges that were not worth gathering at the time 

 of cessation to grow to respectable dimensions. 



Commercial sponges may be divided into two very dis- 

 tinct groups, the toilet-sponges (Spongia), and the coarser 

 bath-sponge {Hippospo7igio) . lu the members of the former 

 group the inhalent pores are situated over the whole of the 

 outer surface ; while the oscula, or waste-pipes, form much 

 larger cylindrical apertures on the upper surface, which 

 may be cup-shaped. Of this group two species may be 

 recognized, namely the soft toilet-sponges (S. ojlirinalis) 

 and the hard toilet-sponges (S. :imocca) ; each of these 

 being again divided into a number of sub-species. And 

 here it may be mentioned that the experienced sponge 

 dealer distinguishes many more varieties of sponges than 

 are at present admitted by the naturalist. 



The finest and most expensive of all the commercial 

 descriptions is the fine Turkey toilet-sponge {S. officinalis 

 typicii), found in greatest perfection off the coasts of the 

 Levant, where it assumes the well-known cup-like form 

 The average wholesale price of picked specimens of this 

 description ranges from five to nine shillings each. Next 

 in value are the so-called " Turkey solids " {S. ofjicinalis 

 adriatica), in which the cup-shape is lost and the top of the 

 sponge is flat. These are the only kind of Turkey found 

 to the westward of Malta. Their wholesale price is from 

 two shilHngs to half-a-crown each. In these sponges the 

 apertures of the waste-pipes are larger than in the Turkey 

 cups. Another remarkable variety of this species is the 

 lago-fitxis, or elephant's ear sponge (S. officinalis lamella), of 

 the Adriatic. These form huge fungus-like lappets, which 

 sometimes join at the edges so as to produce large open 

 cups. Cut into small pieces they are used for house- 

 cleaning, but the most important use of the larger sizes is 

 for certain surgical operations ; they are also employed 

 for stuffing saddles. The wholesale price of the best 

 descriptions varies from thirty shillings to sixty shillings 

 per dozen. 



In American waters the Turkey cup is unknown, the 

 only cup-shaped American sponge occurring in the Gulf 

 of Florida, and more especially at Tarpon Springs. The 

 West Indian representative of the Turkey toilet is the 

 glove-sponge (S. oflicinalis tuhuUfera) (Fig. 1), which 

 tends to grow in a number of finger-like processes, each, 

 when fully developed, terminating in the aperture of a 

 large waste-pipe. The best descriptions fetch half-a-crown 

 per pound wholesale. The fine reef-sponge of the West 

 Indies is another variety of S. officinalis, which assumes 

 neither a cup nor a finger-shape, but is generally some- 

 what pyramidal and pointed, with the apertures of 

 the waste-pipes forming distinct prominences. Very 

 characteristic of the West Indies is the grass-sponge 

 {S. oficinalis punctata). The ordinary form (Fig. 2) is 

 cylindrical, with a flat upper surface ; the border of that 

 surface, like the sides, is of fine texture and perforated by 

 the inhalent pores, but the centre is occupied by the numerous 

 small and closely crowded apertures of the waste-pipes. 

 The margins of these apertures are more or less prolonged 

 into a delicate lace-like fringe ; and in one sub-variety, 

 locally known as pAiido (hair), these prolongations take 

 the form of delicate cups. The Florida grass-sponge is a 

 sub-variety which assumes a cup-shape, the waste-pipes 

 all opening within the cup. 



Passing on to the hard toilet-sponges, we find these easily 

 distinguished by their denser and less resilient texture ; 

 this being due to the greater thickness of their component 

 fibres. In all essential features they agree, however, with 

 the soft toilet-sponges ; the sides being perforated by the 

 pores alone, while the waste-pipes open among the pores 

 on the upper surface. The species is typified by the 



