CHAPTER IX ON CONCRETIONS, SPICULES, AND SPICULAR SKELETONS

We know that their tensions will tend to conform them into a 〜honeycomb,〝 or regular meshwork of hexagons, and that the free end of each hexagonal prism will be a little spherical cap. Suppose now that it be at the outer surface of the protoplasm (that namely which is in contact with the surrounding sea-water), that the siliceous particles have a tendency to be secreted or adsorbed; it will at