Note 33 — THE NORTH AMERICAN SLIME-MOULDS (continued 3)

If a sporangium of L. tigrinum be mounted in water and treated to weak solution of hydro-chloric acid we may easily discover that the crystals, which so wonderfully adorn the outer wall in this and other species, consist, in part at least, of calcium carbonate. We may also discover that in the case before us the crystal or scale lies indeed enclosed in a filmy sac of organic origin, and that could we have seen the outer peridium as it came to form, we might probably have found it made up largely of an ectosarcous foam in whose cavities the excreted calcium found place for tabulate crystallization. In other species listed, conditions are different, and the crystals assume a different shape. The phrase "bicarbonate of lime" quoted in this connection in the former edition of this work from Mr. Massee's Monograph, etc., is not clear.