DEEP-SEA SPONGES. 419 



Over an enormous extent the abyssal ocean bottom is found 

 covered with a sheet of almost formless beings, absolutely devoid 

 of internal structure, and consisting merely of living and 

 moving expansions of jelly-like matter. Whether this form of 

 life, still more simple than the Amoeba,* to which Professor 

 Huxley has given the name of Baihybius Haeckelvi, be con- 

 tinuous in one vast sheet or broken up into circumscribed 

 individual particles, it is equally an object of wonder ; and as 

 no living thing, however slowly it may live, is ever perfectly 

 at rest, it shows us that the bottom of the sea is, like its surface, 

 the theatre of perpetual change. 



Living among and upon this Bathybius we find a multitude 

 of other protozoa, foraminifera and other rhizopods, radiolarians, 

 and sponges. 



Such is the countless number of the Foraminifera inhabiting 

 the deep seas, that their remains form the chief mass of the 

 soft oozy bottom of the ocean. In the surface layer of the 

 deposit the shells of Globigerina bulloides, the prevailing 

 species, are found fresh, whole, and living, and in the lower 

 layers dead and gradually crumbling down by the decompo- 

 sition of their organic cement and by the pressure of the 

 layers above. Countless generations are thus piled one upon 

 the other ; and each successive stratum, weighing upon those of 

 older date, is laying the foundation of future rocks, which sub- 

 sequent revolutions may perhaps heave out of the deep and 

 raise in towering pinnacles to the skies. 



Sponges f of wonderful beauty and lustre appear to extend 

 in endless variety over the whole of the bottom of the sea. 

 Some (Holtenia Garpenteri) anchor in the ooze by means of a 

 perfect maze of delicate glassy filaments, like fine white hair, 

 spreading out in all directions through the sea's fluid mud; 

 while others (Hyaionema) send right down a coiled whisp of 

 strong spicules, each as thick as a knitting-needle, which open 

 out into a brush as the bed gets firmer, and fix the sponge in 

 its place somewhat on the principle of a screw-pile. " A very 

 singular sponge, from deep water off the Loffoden Islands, 

 spreads into a thin circular cake, and adds to its surface by 

 sending out a flat border of silky spicules, like a fringe of white 



* See Chapter VIII., p. 380. t Ibid. pp. 385-389. 



F F 



