Miller has recently applied the name cysto sarcoma to growths, principally composed of a fibro-vascular texture, but invariably found to contain solitary cysts in their substance. The cysts may be solitary or compound ; the solid substance, of greater or less density, has an indistinctly fibrous structure, contains no cells, and is ofalbuminous basis. This growth is essentially distinct from carcinoma, but that it differs generically from sarcoma seems ques tionable.
Secondary cysts are not spontaneously generated, but term through the influence of bodies foreign to the site they occupy : around effused blood, after a series of modifications (the apoplectic qst), around adventitious pro ducts, extra-uterine fcetuses, and bodies intro duced from without, as musket-balls, shot, pins, Sze.
A sort of pseudo-cyst is sometimes produced by distension and closure of small natural cavi ties, or of the excretory ducts of glands. In the first class we find dilated cutaneous follicles, intestinal crypts and solitary glands; to the second class belong cysts of the lactiferous and pancreatic tubes, of the labial and sub maxillary glands, some of those in the testicle, and, it is commonly believed, in the kidney.*
Fibrous and Elastic the production of white fibrous-tissue of an im perfect kind, numerous examples have been referred to in the past pages,— it is one of the commonest of new formations.
Less common by far is the generation of the yellow fibrous element, which is distinguished by resisting the action of acetic acid ; the mesh-like arrangement of bifurcated fibres is much rarer in the imitation new tissue than in its prototype,— nor does the former occur (so far as we know) in masses of any size. The modification of this texture which con stitutes the main element of artery is doubtless produced in new vessels.
Osseous most perfect imitation of a complex natural texture is ex emplified by adventitious bone,— produced for the reparation of injuries (Permanent Callus). It is even said that the permanent callus has all the characters of true bone,— a proposi tion which appears to us to require more absolute proof than it has yet received. The new bony shaft, produced to Ripply the ravages of necrosis of' the long bones, is a ruder imitation of original bone ; it is darker in colour, rough, and tuberculated on the surface, and often much denser than the latter. (See