DEEP-SEA SPONGES. 419 
Over an evormous 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 Amceba,* to which Professor 
Huxley has given the name of Bathybius Haeckelii, 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 muy 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 Carpenter’) 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 (Hyalonema) 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. ¢ Ibid. pp. 385-389, 
FF 
