THE BEAUTIFUL LADDER. l6l 
lated city of millions of tiny and strange inhab¬ 
itants. Found alive and bedded in its native 
sea-bottom, the Spongia is one of the great 
wonders of ocean-life. Soft as the texture of 
the prepared sponge seems to be, it is neverthe- 
Jess made up of two very hard substances—sil¬ 
ica and another closely resembling the horns of 
animals. The spicules of silica are marvels of 
shape and sharpness, and it is a wonder how 
they can exist in a substance so soft and flex¬ 
ible. Look carefully at a sponge, and it is 
found perforated with countless pores, every 
one of which was the home-dwelling of a liv¬ 
ing polyp, whose life-throbs made the spongy 
mass one enchanting scene of living fountains. 
Professor Grant, who paid special attention to 
the habits of this denizen of the sea, says: 
‘ The beauty and novelty of such a scene in 
the animal kingdom arrested my attention, 
until I was obliged to withdraw my eye from 
fatigue.’ And no wonder, for the gaze, once 
fixed upon such a phenomenon, feels the spell 
of an enchantment from which alone exhaus¬ 
tion of the power of the optic nerve could 
bring disenthralment. 
“ On the attractive claims of the sea-stars 
14 * L 
