The _fibrous_ or _scirrhus_ form of the disease, is by far more commonly met with than any other, although it may be found occasionally combined with the medullary, or both these with colloid. Indeed, it is not improbable, but that in many cases, a growth originally scirrhus, becomes gradually converted into one of the other forms. In almost all cases, cancer commences in the submucous tissue, in the form of a dense mass, of a white color. When cut, the surface presents a whitish-gray appearance, contrasting strongly with the vascular mucous membrane of the stomach, and presenting a distinctly striated appearance. A small portion under the microscope, or the juice scraped from the cut surface, will show the peculiar cancer cell, with granular matter. _Encephaloid_ or medullary cancer, may be developed upon or within the fibrous form, or it may occur primarily as knotty tumors projecting through the mucous membrane. The microscopic appearance is much the same as in the fibrous variety, except that the cells are not so closely packed, but are loosely held together by an abundant, soft, or liquid substance. The _colloid_ form of the disease, may originate either in the mucous membrane itself, or in the submucous tissue. It is known by its presenting a tough, fibrous-looking, white tissue, which, arranged in intersecting bands, incloses irregular spaces, which are filled with a clear, soft, or semi-liquid material, the proper colloid substance. The _villous cancer_, Dr. Brinton describes as arising in the basement membrane of the mucous coat, and as but a modification of the epithelial cancer of other parts of the body. The mucous membrane covering cancerous growths, is subject to a variety of changes. It may become converted into a sort of fungoid growth, which at points suppurates, showing the submucous scirrhus tissue; or it gradually softens, giving rise to hæmorrhages. The cancerous mass itself, may also soften or suppurate, resulting perhaps in perforation and peritonitis; or adhesions may take place, followed by extension of the disease to the liver, spleen, pancreas, kidneys, etc. Cancer of the stomach, in the great majority of cases, occurs in persons between fifty and sixty years, although it may appear as early as forty, or as late as sixty. Males appear to be more subject to the disease than females, in the proportion of four to three. The _obstruction_ which the presence of cancer of the stomach is liable to produce, may result in one or more of the following conditions: First, _hypertrophy_ of the muscular coat. From increased nutrition, the muscular fibres of the stomach may become considerably increased in size and darker in color, thus better enabling them to overcome the obstruction, which in some cases, amounts almost to occlusion.