The deeper and more active layer of the epidermis, the mucosum, is made up of cells some of which contain minute granules of pigment, or coloring matter, that give color to the skin.

On examining the paper photographs, we have found no distinct granules, but diffused stains of deeper or lighter shades.

On examining the glass negative by transmitted light with a power of a hundred diameters, we observe minute granules, whether crystalline or not we cannot say, very similar to those described in the account of the daguerreotype.

The adjacent sporangia also become cut off by septa, and the investing membrane, when mature, opens: it a beak-like prolongation, thus permitting the inclosed densely congregated green granules to be penetrated by the antherozoids which swarm from the antheridium at the same time.