Other Vesicles, again, consist of three or of four, the inner, secondary, and tertiary ones being by turns central and extra-centrical. This species of complex and involved sheathing is met with in very small (1/266th millimetre-sized) vesicles. In some of the simple vesicles is found, - in place of a wall-inclined, secondary, spherical vesicle, - an oblong, wall-attached nucleus.

(d.) With these are associated many-layered, smooth, or slightly gibbous cysts, between the lamellae of which oblong nuclei are often found inserted. The central vesicle occasionally holds a multitude of the most various primary and secondary forms, - elementary granules (nucleoli); spherical, oblong nuclei; simple and compound vesicles, and incrustations of vesicles. These laminated growths, for the most part, undergo an incrustation proceeding from the central layers.

(e.) We also find the cysts of the vascular plexus to contain commonly in the shape of a mucus-like substance, deposited, as it were, from the fluid, and mostly infiltrated with fine sand-granules, a transparent blastema pervaded with round and oblong nuclei. This gradually forms into areolar tissue, displaces the moisture, and ultimately fills up the entire space of the cyst, in the meshes of which the aforesaid forms all lie imbedded. Within the structureless blastema we perceive the oblong nuclei bent in accommodating curves around, and closely attached to, the vesicles (alveolar textural arrangement). Such cysts gradually shrivel around these their contents, and finally become extinct.

The aforesaid cysts are very delicate, commonly clear and transparent; some refract the light with a whitish tone, their contents appearing somewhat denser; in others, the contents are of a reddish shade; in others, again, finely granular, as though coagulated; in others, lastly, the contents consist of a multitude of sharply-defined granules. To this class belong, more especially -

(f.) Globular bodies, in which the outline of a cyst-wall is wanting, and which represent lightly granulated spheres.

(g.) Lastly, the vascular plexus cysts often contain a whitish, chalky fluid. This consists almost entirely of fat-globules, and gradually thickens into a lardaceo-cretaceous pap, around which the cyst speedily shrivels, and perishes.