Life can only express itself in concrete form; it is inseparably linked to a material substance, and this substrate, on which all life processes take place, is formed by cells and their derivatives. All living organisms consist of cells and their derivatives. The cell itself appears in its original form as a microscopic, mostly uncolored lump made up of a slimy, pale, finely granulated substance known as protoplasm. In presenting the anatomical changes of organs and tissues, I have made an effort to adequately consider the results of both macroscopic and microscopic examinations. To make the latter more understandable, I deemed illustrations essential. I have dedicated special attention to the histogenesis and etiology of various affections.