13. =Adenoid Tumors.= The _Adenomata_ are new formations of gland tissue, resembling in structure the racemose, or tubular glands. “They consist of numerous small saccules or tubes filled with squamous or cylindrical epithelial cells. These are grouped together, being merely separated by a small, though varying amount of connective tissue, in which are contained the blood-vessels.” They are essentially local hyperplasias. The new growth may remain in intimate relation with the adjacent gland, or it may gradually become separated from it by the formation of a fibrous capsule. The adenoma is usually a solitary tumor, of a firm, dense, inelastic consistence, of a whitish, grayish, or pale straw color, seldom larger than a hickory nut. On section, the cut surface has a glistening appearance, and in recent cases never yields any fluid on pressure. It occurs in the mammary, thyroid, prostate, and parotid glands, and in the mucous follicles. In mucous surfaces, it gradually projects above the surface of the membrane, so as to form a polypus, and thus constitute the most common form of mucous polypus. 14. =Lymphatic Tumors.= “The _Lymphomata_ are new formations consisting of lymphatic, or as it is more commonly called, _adenoid_ tissue. This tissue consists essentially of a delicate reticulum, within the meshes of which are contained the so-called lymph corpuscles. The reticulum is made up of very fine fibrils, which form a close net-work, the meshes of which are only sufficiently large to enclose a few, or even a single corpuscle in each. The fibrils usually present a more or less homogeneous appearance, and amongst them there are a few scattered nuclei.” The lymphatic tumor is most frequently met with in the lymphatic glands of the neck, axilla, groin, and mesentery, and usually consists of several enlarged glands, fused into one common mass of variable size, shape, and consistence. The sectional surface is of a grayish, light pink, or reddish-yellow color, and yields on pressure a whitish, lactescent juice, not unlike that of certain forms of carcinoma, containing cells with one or more nuclei. II. Malignant Tumors. 1. =Sarcomatous Tumors.= The _Sarcomata_ are tumors consisting of embryonic connective tissue. This differs from the fully developed tissue, in consisting almost entirely of cells, which are also larger and rounder than those of mature tissue. Its intercellular substance, instead of being fibrous, is soft and amorphous or only obscurely fibrillated. The cells of sarcoma are round, spindle-shaped or stellate, and exist either separately or in conjunction in the same tumor. The latter is most frequently the case; but one form generally predominates, and according to the preponderance of one or the other kind of cell, these tumors can be most conveniently classified as round-celled, spindle-celled, and giant-celled sarcomata.