SPONGES. 



in a calm sea. Handfuls of sand steeped in oil are 

 thrown into the water all around the fishing-boat ; the 

 oil spreads over the surface, and sniootliens it, by neut- 

 ralizing the action of the atniosplicre. The fishers 

 can then see distinctly the sponges clinging to the 

 ocean bed. 



Sponge fishing is also carried on in the Gulf of 

 Mexico, on the Bahama banks ; the divers being Eng- 

 lish, American, and Spanish. As in this region the 

 sponges grovf at an inconsiderable depth, the divers 

 have only to let themselves drop along a mast or pole 

 moored to the boat's side. 



The fishing being over, the boatmen press the 

 sponges tightly, tread them under foot, and wash them 

 repeatedly, first in sea-water and afterwards in fresh 

 water, until they are entirely cleansed from their gela- 

 tinous mucus. Afterwards they are soaked for a short 

 time in hot water, to free them as much as possible 

 from the chloric odour peculiar to them, and due to 

 tlie animal matter absorbed in their fibrous tissue. 



The various kinds of sponges which figure in com- 

 merce are distinguished by diSerences of appearance 

 and texture. 



The fine soft Syrian Sponge is remarkable for its 

 lightness, its blonde colour, its cup-like form, and its 

 peculiar surface; which is convex, voluted, and pierced 

 with innumerable minute orifices; the convex part 

 furrowed by considerably larger canals, that pierce 

 through the entire mass. This sponge is occasionally 

 blanched by means of caustic substances, acids, or 

 alkalies ; but this process changes its colour and renders 

 it less durable. It is used for toilet-purposes, and itd 

 price is high. 



The Fine Sponge of the Archipelago can hardly be 

 distinguished from the Syrian, either before or after it 

 is cleansed ; it is, however, of greater weight, of 

 coarser texture, and pierced with fewer but larger 

 holes. 



The Hard or Greek Sponge is inferior to boih the 

 preceding, but has its value for domestic and certain 

 industrial purposes. Its mass is irregular, its colour 

 fawn ; it is hard, compact, and pierced with small 

 holes. 



The White Sponge of Syria, called Venetian, is 

 esteemed for its lightness, solidity, and regularity of 

 form. In its rough state it is brown of colour, fine in 

 texture, compact, and firm. When purified, its tex- 

 ture becomes looser, and its colour yellower. The 

 orifices of the great furrows or tubes which penetrate it 

 are lined with rough bristly hairs. 



The Brown Barhary Sponge, or Marseileise, when 

 first brought from the water, is a flattened elongated 

 body, gelatinous, circular of shape, and charged with 

 blackish mud. It is then coarse, hard, heavy, but 

 compact, and of a reddish colour. By simply washing 

 it in water it becomes round and globular, but still 

 remains heavy and reddish. Owing to its facile ab- 

 sorption of water and remarkable strength, it is much 

 esteemed for domestic uses. 



Other sorts of sponge are very abundant. 



These are — the Blonde Sponge of the Archipelago, 

 which must not be confounded with the Venetian ; the 

 Hard Barhary Sponge (or Gelina), occasionally im- 

 ported into England ; the Salonica Sponge, which is 

 only of medium quality; and the coarse, cheap, Bahama 

 Sponge from tlie West Indies. 



Regarding Sponges as apolypiferous zoophytes, Dr. 

 Grant has arranged them in the following groups : — 



I. Groups of which the Constituent Structure is 



known. 

 Spongia; Calcispongia; Halispongia; and Spongilla. 



II. Groups depending on Characters of Surface 



or General Figure. 

 Geodia ; Coeloptychium ; Siphonia ; Myrmecium ; 

 Scyphia ; Eudea ; Ilalirrhoa ; Happaliraus; Cne- 

 midium ; lerea ; and Tethiuni. 



0^ 



