Variability in the X-ray Diagram of the Cell Walls of the Marine Alga Spongomorpha

IN a recent communication1 we have shown by the methods of X-ray analysis that the two closely related green algae Cladophora and Spongomorpha differ fundamentally in the submicroscopic organization of their cell walls. Whereas the cells in Cladophora filaments have walls in which the skeletal substance is a highly crystalline, well-oriented native cellulose (cellulose I), those of Spongomorpha contain a poorly crystalline, scarcely oriented modification of cellulose which might be mercerized cellulose (cellulose II) or a derivative. It was pointed out some time ago2 that the air-drying of the material, necessary for X-ray investigation, does not produce any undesirable artefacts in algae, and it was therefore concluded that the structures derived in this way could legitimately be applied to the fresh material. Even preservation in formalin or alcohol does not cause any observable change in the X-ray diagram.