BENEATH TROPIC SEAS 



fifty -pound capture was a sponge, but each of the 

 many groups of lashing-cell canals had its own 

 private exit canal, and might perfectly well be con- 

 sidered a separate organism. In some ways the 

 schism between these groups is greater than be- 

 tween some organisms wholly separated, such as 

 individual army and leaf -cutting ants. Some day, 

 very wonderful discoveries will be made of the bind- 

 ing power of relationships too intangible to be per- 

 ceived by either sight or touch. Meantime, not 

 further to confuse my sanity, I propose to call my 

 giant of the reef, a single sponge. 



While no sponge has a skeleton comparable with 

 our bones or even with a grasshopper's armor, yet 

 the whole body mass of horny or jelly-like tissues 

 is supported by a maze of stony spicules. In shape 

 they are like rods, bows, anchors, pick-axes, arrows, 

 snow-crystals, stars, crosses, prongs, boomerangs, 

 forks, triangles and needles. They are sometimes 

 arranged in beautiful order, or again scrambled 

 regardlessly through the sponge like piles of jack- 

 straws. They may be made of silica or lime, or 

 as in the case of bath sponges, replaced by a frame- 

 work of horny consistency. 



Consider, for a moment, the amount of silica in 

 seawater, less than two parts in every hundred 

 thousand. And yet the tangle of spicules in 

 sponges is derived from this infinitesimal amount. 

 To form a single ounce of silicious spicules the 

 patient sponge has to swallow a ton of water. We 

 know nothing of the process; we can imagine only 



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