“The inner surface of the parasite is studded with numerous little bodies, resembling diminutive fish-spawn, hardly as large as a grain of sand, of a spherical shape and of a grayish color, each consisting of a delicate cyst, filled with echinococci.” “Each echinococcus consists of a body and a head, the latter being encircled by a row of teeth, naturally concealed in a narrow cleft, but capable of projecting itself. The body, composed of solid, granular matter, has a curiously speckled appearance, due to the presence of numerous ovoid spots immediately beneath its outer coat. The teeth, or hooklets, are spinous, sharp, and perfectly characteristic.” 3. =Myxomatous Tumors.= The _Myxomata_ or mucous tumor, consists of mucous tissue, a translucent and succulent connective tissue, the intercellular substance of which yields mucin. Their characteristic features are elasticity and softness; the older growths, however, are harder than the more recent ones. They are of a pale, greyish or reddish-white color. They consist of a basement structure, the proper stroma of the tumor, and an intercellular substance, pervaded by distinctly visible blood-vessels. On being cut, they yield, on pressure, the tenacious, mucilaginous, intercellular liquid, in which may be seen the cellular elements of the growth. The majority of the cells, under the microscope, are found to be angular and stellate, with long, anastomosing prolongations and trabeculæ. Others are isolated and fusiform, oval or spherical in shape. They usually possess one, in some cases two distinct nuclei. Fat cells, fibrous tissue, both white and elastic, and cartilage in varying proportions, are often met with in the morbid mass. They occur chiefly in the subcutaneous and intermuscular cellular tissues, in the mucous cavities, in the hilus of the kidney, and in the nerves and bones. When situated in superficial parts they may become pedunculated. In the submucous tissue of the nose they constitute the gelatinoid polypus. Other perfect types of mucous tumors are seen in the polypi of the ear and the uterus.