SPONGE-DIVING. 49 



from which they are not detached without con- 

 siderable effort. In several of the Greek islands, 

 the inhabitants have been trained from their infancy 

 to dive for sponges. The extraordinary clearness 

 of the water facilitates their operations. At the 

 Cyclades, sponge-diving forms the chief employ- 

 ment of the population. The sea is at all times 

 beautifully clear, and the experienced divers are 

 capable of distinguishing from the surface the points 

 to which the sponge is attached below, when an 

 unpractised eye could but dimly discern the bottom. 

 Each boat is furnished with a large stone attached 

 to a rope, and this the diver seizes in his hand, on 

 plunging head foremost from the stern. He does 

 this in order to increase the velocity of his descent ; 

 thus economizing his stock of breath, as well as to 

 facilitate his ascent when exhausted at the bottom, 

 being then quickly hauled up by his companions. 

 Few men can remain longer than about two minutes 

 below ; and as the process of detaching the sponge 

 is very tedious, three, and sometimes four divers 

 descend successively to secure a particularly fine 

 specimen. 



The canals and pores of a living sponge are filled 

 with a fluid resembling the white of an egg, varying 

 in quantity according to the species. When a 

 drop of it is examined under a microscope, it 

 appears entirely composed of very minute transpa- 

 rent grains, either spherical or ovate, nearly all of 

 the same size, with some moisture. The fibrous 



