The carcinomata also possess lymphatics, and it is owing to this that the lymphatic glands are so constantly involved in the disease. Cancers very rarely become encapsuled, but generally invade the surrounding structures. The epithelial elements are found infiltrating the tissues for some distance around the tumor, so that there is no line of demarcation between it and the normal structures. Carcinomatous tumors are liable to certain alterations and transformations, like other morbid growths. Fatty degeneration is the most common of these. This occurs to a greater or less extent in all the varieties of cancer. It produces softening of the growth, which is often reduced to a pulpy, cream-like consistence. Calcareous degeneration has been occasionally met with in encephaloid, and in carcinoma invading bone. Inflammation, softening, and consequent ulceration, are not unfrequent. The varieties of carcinomata are: (_a_.) _Scirrhus._ Scirrhus, fibrous, hard or chronic cancer, seldom occurs before middle age, and more frequently in the female than male. The liver, mammæ and uterus, are particularly liable to be attacked. It also occurs in the alimentary canal, and in the skin. Scirrhus is characterized by the large amount of its stroma, and its slow growth. The tumor is firm, hard and inelastic, of variable shape, and is often depressed in the centre, owing to the contraction of the cicatricial tissue. On section, especially in the more matured stages, the tumor exhibits a whitish, glistening aspect, intersected with fibrous bands, the remains of normal tissue, changed by disease. It yields on being scraped, a peculiar fluid, the so-called cancer juice, generally of a pale, grayish, turbid appearance, rich in cells, nuclei and granules, sometimes of a whitish, creamy hue. This juice is evidently the result of disintegration, and is hence but sparingly present in recent specimens. It readily mixes with water, and often contains a quantity of free oil. Scirrhus has but few blood-vessels. Nerves and lymphatics also exist. It has a tendency to ulcerate, and to contract adhesions with the structures surrounding it. The lymphatic glands are also liable to be infected, by the conveying of cancer elements to them through the lymphatic vessels situated in the scirrhus mass. (_b._) _Encephaloid._ Encephaloid, medullary, soft or acute cancer, differs from the preceding, in the small amount of stroma, the consequent softness of consistence, and its rapid growth. It is most common in the mammæ, eye, testicle, uterus, liver, lymphatic glands, periosteum and bones. The greatest number of cases occur between the twentieth and fiftieth years. The cells are exactly similar to those of scirrhus, but far more numerous, while the stroma is not so well marked, and much less fibrous, and does not undergo a similar cicatricial contraction. Blood-vessels are very abundant.