The Presence Of All The Semi-Transparent And Opaque Formations renders the cyst-contents whitish, or turbidly yellow. This portion of the cyst's contents is frequently separated in the form of a deposit.

With this I conclude the catalogue of facts, relating to the cyst. I shall now proceed to recapitulate these facts, and endeavor to elicit from them such deductions as they appear to warrant and uphold.

1. The cyst is, with respect to its organization and secretory function, an independent hollow growth, essentially based upon a substantive element.

2. At the characteristic turning-point, between a primary (embryonic), and a secondary phase, overstepping the microscopic scale, the cyst consists of a structureless vesicle of from 1/25th to 1/10th of a millimetre in diameter, and an encircling fibrous layer, maintaining various grades of development. To these is added, as endogenous production, a nucleus or cell-formation, limited to an epithelial stamp. The cyst here completely resembles the glandular vesicle of the thyroid gland, and of the supra-renal capsules. The encircling fibrous layer furnishes the alveolus for the reception of the structureless cyst.

3. The elementary germ of the structureless vesicle, resides in the nucleus, - nay, inasmuch as the nucleus is obviously generated out of an elementary granule, it resides in the elementary granule itself. The latter grows by intussusception into the nucleus, and the nucleus at once in the same wise into the structureless vesicle. The nucleus arising out of the elementary granule either retains the character of the latter, as a smooth, polished, sharply-pencilled vesicle, or acquires the well-known granulated character. It is obviously the former, in particular, that becomes developed into the structureless cyst, even the granulated nucleus, however, enters upon this development, its contents clearing up during the process, but resuming the granulated character afterwards.

This history of cyst-development is essentially corroborated by the expansion of the cell-nuclei, of so frequent, although by no means exclusive, occurrence in cancer-cells; an expansion first pointed out with precision by Virchow, but which, owing to the identity of development of the normal gland vesicle, and of the cyst, cannot be regarded as heteroplastic. It consists in the development of the cell-nucleus into a comprehensive cyst, identical with that evolved out of the naked nucleus.

This corroboration is rendered complete by the fact, that, in the inflated cell-nucleus, an elementary granule present as a nucleolus, expands into a nucleus, generates within itself another neucleolus, and forthwith becomes a second cyst. This in my opinion affords important evidence of the vesicular nature of the nucleus, and of its evolution out of the elementary granule, through simple intussusception-growth which Bernhardt has shown to be a property of the chyle-, the lymph-, and the pus-corpuscles. (See Virchow's Archiv., vol. 1, fas. 3).

4. To the cyst in its primitive condition, as a structureless cyst, there accedes from without, and blends with it, a more or less marked fibrous texture. The cyst in this secondary condition, consists of a wall of a definite texture, with an internal lining of epithelium, and is at once endowed with an enormous capacity of growth.