early stages of calcification in a molluscan (Fig. 198), or still more in a crustacean shell20; while in their isolated condition {423} they very closely resemble the little calcareous bodies in the tissues of a trematode or a cestode worm, or in the oesophageal glands of an earthworm21.
When the albumin was somewhat scanty, or when it was mixed with gelatine, and especially when a little phosphate of lime was {424} added to the mixture, the spheroidal globules tended to become rough, by an outgrowth of spinous or digitiform projections; and in some cases, but not without the presence of the phosphate, the result