Osteoid tumors, in Rokitansky's opinion, are simply cancers, in which the stroma has undergone true ossification. This view is favored by the fact, that similar tumors are very apt to develop themselves in other and internal parts, whether the original growth has been removed or not. Lebert, however, distinguishes them from cancer, and, from the accounts which are given of their structure, not without reason. They are described as tumors of irregularly protuberant surface, sometimes of rapid, sometimes of slow growth, occasionally attaining a very considerable magnitude, and originating (the primary ones) from some bone. In structure, they consist of a cancellous bony tissue, which is plunged amid a grayish white, vascular, fibrous material, in which a sparing quantity of cells and nuclei are discernible. This substance seems to be similar to the ossifying basis of the cancellous tissue, and yields, on boiling, neither gelatin nor chondrin. The bony skeleton of an osteoid tumor may predominate more or less, so that the structure may be like compact or spongy tissue. Varieties in this respect may be observed among the different tumors in the same individual. Osteoid tumors have been found in the cellular tissues, the serous membranes, the lungs, the lymphatic glands, and in the interior of the great vessels. From these and other facts, Lebert arrives at the rather vague conclusion, that the cause of the appearance of these tumors is a general osteoplastic diathesis. This does not advance our knowledge much, and, besides, we doubt whether it touches the principal point, which is, to know whether the tumor is essentially a bony tumor, the fibrous part serving only as an ossifying basis, or whether the bony formation, though constant, is secondary and inferior in importance to that of the soft matter? Further observations must determine this. We may mention, that the name osteo-sarcoma is given to encephaloid tumors, originating from bone, and receiving into their mass long thornlike or stalactitic or radiated offshoots of bone, from the natural tissue in the vicinity. These, in some cases, may resemble very much the arrangement of the bony portion of osteoid.

CYSTOID TUMORS.

These constitute a very large and important class of new formations. They agree in the one general character, that they form receptacles which are filled with various contents, but in other respects they present very great diversity. We shall separate them at the outset into two divisions, the one comprising cysts, which result from the distension of a natural pre-existing cavity, the other those which are entirely new formations. Under the first head we notice: (1.) The common socalled encysted tumors, which occur so often on the scalp and elsewhere. These are essentially sebaceous follicles, whose orifice has become obliterated, and the cavity in consequence, distended by continually accumulating secretion. The contents of these cysts are of very different appearance, and the names of meliceris, hygroma, atheroma, gummy tumor, have been given to express a honey-like, watery, pultaceous, or jelly-like condition of the retained secretion. Examined microscopi

cally, epithelial scales, free fatty matter, tablets of cholesterin, crystals of triple phosphate, and small hairs in various proportions, the epithelium, however, usually predominating, are found to constitute the contents of these cysts. The cyst itself appears as a thin fibrous layer, lined on its inner side with epithelium. We have seen one case in which the epithelium in several tumors had accumulated in a very thick layer on the interior of the true cyst, giving rise to the appearance of a thick-walled cavity with contained matters of the ordinary kind; microscopic examination, however, showed that there was no real thickening of the cyst itself. The scaly particles of epithelium seem to fill themselves occasionally with a pellucid refracting matter, apparently of oily nature; they are mingled in some cases with granular globules, not unlike pus-corpuscles, or if inflammation has occurred, with pus itself. This, at least, is the case with comedones, which are of a similar nature. (2.) Mucous encysted tumors; these are essentially similar to the preceding, and are formed by obstruction of the duct of a mucous follicle, or small conglomerate gland. They contain usually a glutinous mucous fluid. They occur in the lips, the mouth, in the cervix uteri, the Meibomian glands, and in the vagina. Ranula is an exactly analogous affection of the duct of the sublingual gland. (3.) Some of the renal, and mammary, and probably most of the hepatic cysts are produced in the same way, by local obliteration of the duct canals at two points, and distension of the intermediate portion. (4.) Single cysts in the ovary are perhaps formed by dropsical distension of the Graafian vesicles; this may also be the origin of others which are afterwards compound. (5.) Cysts in the thyroid gland are, no doubt, often formed by simple expansion of the normal vesicles. (6.) Certain bursæ (not of new formation) become distended by a persistent increase of their secretion, and constitute cystic tumors. Mr. Simon states that the contents of these, instead of being fluid, are occasionally solid, the albuminous secretion having been replaced by a fibre forming (probably fibrinous) blastema.

Under the second head, we notice: (1.) Simple serous cysts, and synovial bursæ. These arise in some cases evidently from the effect of pressure or friction, in others without any such cause. In the former case, we observe that a kind of condensation takes place in the areolar tissue of the part, making out the limits of the commencing bursa; within this the fibrous bands are gradually absorbed, while a secretion at the same time of fluid takes place, and at last the cavity is lined by a more or less perfect epithelium, and the new formation is complete. We can discern the purpose for which such cysts are formed, the end they serve, but we have no idea of the nature of the action which determines their formation. With regard to the others, which form in situations removed from pressure, as in the broad ligament of the ovary, the cause of their production is utterly unknown. They consist of a wall of fibrous tissue, varying in thickness in some measure, according

We found the contents of an encysted tumor of the eyelid, operated on by Mr. White Cooper, to consist of a colorless, translucent matter, made up of multitudes of delicate granulous globules, imbedded in a clear fluid, which was coagulated in some measure by

acetic acid.

to the size of the cyst, condensed so as to form a smooth surface internally, and lined by a thin layer of epithelium, which has generally appeared to us to consist of nuclear particles, with imbedding granulous matter, and not of perfect cells. The import of this condition of epithelium appears to have reference to the rapid secretory action which takes place. The fluid contents of these cysts may be poor or rich in albumen, may contain abundance of cell forms, or very few, and may be either loaded with cholesterin, or devoid of it. We can confirm the

Simple serous cyst, and epithelial particles from its interior-from vicinity of ovaries.

statements of Mr. Simon, that the granule-cells, which are sometimes very numerous, are the seat of the color of the dark coffee-ground-like matter which is sometimes present in large quantity. Some of these simple cysts contain quantities of fat, hair, teeth, and even bone, so that some good authorities have expressed their belief that they were the remains of a partially absorbed foetus. This is certainly not the case, but their occurrence is of extreme interest, and being peculiar to ovarian growth, suggests very strongly that the normal reproductive function of this organ exerts itself by the development of these productions within its germ-bearing cavities, under the influence of some unnatural stimulus. This, of course, applies especially to the cysts alluded to under the first head, as developed from the Graaffian vesicles; but it is Rokitansky's opinion, that cysts of new formation may develop like products also. Mr. Paget states, that in these cases the wall of the cyst acquires in some part the character of true skin, with hair follicles, sebaceous, and sometimes perspiratory glands; and infers that "the structures and secretions formed on this portion of the cyst are shed into its cavity, and there accumulate; and that they remain, when, as often happens, the cutaneous structure on which they are produced has degenerated and disappeared." Several simple cysts may exist together in the ovary; this, we should consider most likely to occur when they result from development of the Graaffian follicles. Simple cysts not unfrequently occur in the mammary gland, or rather in the dense areolar tissue investing it; they have a wall of condensed fibrous tissue, and according to Mr. Birkett, are lined by a characteristic epithelium, consisting of hexagonal particles. Their contents are either limpid, opalescent, non-albuminous fluid, or a tenacious, slimy, opaque, variously colored, and concentrated solution of albumen. When combined with a peculiar growth of gland tissue advancing into their cavity, these tumors constitute the sero-cystic sarcoma, of which we shall speak more particularly when we come to the morbid anatomy of the mammary gland. Cystic formation may take place in various kinds of tumors, in fibrous, carcinomatous, sarcomatous, and may be a more or less prominent phenomenon. (2.) Compound cysts. The chief seat of

these is in the ovaries, where they present two principal modes of development. In one of these the parent cyst, which, for the most part,

Diagram of compound cysts. In the left figure, the secondary cysts are seen growing on the inner surface of the parent. In the right, they have filled up the cavity.

continues to predominate in size, gives origin to a second generation of cysts, and then again to a third, and so on. The consecutive series of cysts are developed in the walls of their parents, but do not grow inward and occupy their cavities; the result is a multilocular mass, made up of numberless cysts, which are filled with very various contents. These may be tolerably limpid and clear, or very viscous and greenish; may contain a very large number of celloid particles, or very few; may be variously colored by blood-globules of new formation, or even replaced by a solid blastema loaded with developing blood; fat, hair, teeth, and bone may also occur in these, as well as in the simple cysts. The partitions between the various cysts sometimes give way, and thus a tumor is produced, which internally seems imperfectly divided into compartments. In the other mode of development, the secondary cysts grow inward into the cavity of the parent, which they fill up more or less completely, a tertiary race behaves toward them in the same way, and so on. This form may be combined with the preceding. Rokitansky describes a kind of villous, or cauliflower growth, which originates on the wall of the secondary or parent cyst, and may increase so as not only to fill the cyst cavity, but to break through its wall, and vegetate in the cavity of the peritoneum.' The impression left on the mind of the observer after a minute examination of the compound cysts, is, that they are of the lowest type of organization, resulting, apparently, from a depraved, degenerate formative action, which, withdrawing blastema from its proper uses in the system, hurries it with a wasteful expenditure into useless and injurious elementary shapes. How precious is the stringency of the law of our organic constitution, which is comparatively seldom infringed by such terrible aberrations! It may be remarked, that the tendency to cyst formation most often appears in the existence of several together; it is certainly far more common to find several, whether of new formation, or resulting from distension of natural cavities, than to find a solitary one. This indicates some special modification of the normal organic action; but we cannot think it is such as Rokitansky points out, when he ascribes all cyst formation, ex

1 In the Report of the Pathol. Society for 1851-52, there is an account, at p. 404, of a growth on the interior of an ovarian cyst which seems to be of this kind. It consisted of vast numbers of pedunculated, clavate, clustered growths, formed apparently of a simple basement membrane inclosing cells."

cept that arising from mere distension, to the extraordinary development of a primary cell.

Sarcomatous tumors constitute a group, which, it must be allowed, is very ill defined. We may describe what we regard as the characters of a typical specimen; but we shall seldom find them all present in any given instance; and, frequently, they will approximate so closely to those of other classes, that we shall remain in some degree of doubt. The fibrous group on the one hand, and the carcinomatous on the other, are the territories which border on the debatable land of sarcoma. The characters attributed to sarcoma are the following: It occurs as a local, for the most part solitary formation, not affecting the constitution. If removed completely, it does not return. In shape it is well defined, roundish, with uneven or lobulated surface, often also branching and

extending itself between the adjacent tissues. Its size varies from that of a hazel-nut to that of a cocoa-nut (Walshe), or perhaps may be still greater. It seems to have no particularly determined site; both maxilla (especially the upper), the interior of bones, glands, muscles, fibrous membranes, submucous areolar tissue, even the brain, are all mentioned as being affected by it. It belongs to an earlier period of life than carcinoma. Softening and breaking down do not necessarily occur in the progress of sarcomata; but if they are exposed, by sloughing of the parts which cover them, they may inflame and saniate, or slough. The commonest variety of sarcoma is that which Rokitansky calls the albuminous fibrous tumor, on account of its yielding, on boiling, no gelatin, but an albuminous matter. The fibres are of various kinds, scarcely different from those of ordinary fibrous tumor. They lie in a diffused albuminous blastema, and are interwoven with a more or less abundant vascular plexus. Another variety is the gelatinous sarcoma, the same which Müller has named "collonema." It is sometimes very