It is, therefore, essential that the student in his undergraduate work should be so trained that, in addition to a broad conception of General Pathology, he may acquire also such a technical knowledge as to fit him to carry on his investigations after leaving the laboratory. Not only in everyday practice in certain lines is a knowledge of this technique necessary for diagnostic purposes, but the true physician should so hold himself toward every problem of diagnosis which presents itself to him, that with every opportunity, he will, through excision, curettage or autopsy, make use of his technical skill to further his knowledge of disease, and to aid his science toward a solution of its great problems. It is for these reasons, that in my laboratory courses in pathologic histology, I wish to give each student a practical working knowledge of the technique of pathologic investigations. That the student become an expert as the result of such undergraduate courses is neither possible nor desirable; it is only hoped that he may be placed in a position to cope intelligently with the questions awaiting him in the field of practice. For the guidance of the student toward this end, I have compiled this little book of laboratory methods, endeavoring to make it as practical as possible, but yet thorough and complete. The methods given are taken from the original papers, or from the compilations of Friedländer and von Kahlden, but are modified in many instances according to the writer’s own experience. The autopsy methods are, in the main, those used by Kolisko of Vienna; but methods of Virchow, Chiari, Nauwerck, and others, are also given. It is from the study of the material itself, and not from the textbook alone, that the student can obtain a proper knowledge of pathologic changes. The most comprehensive textbook can give no adequate idea of the infinite variety of these changes; there is no absolute _type_, but an endless variety of appearances more or less closely related. Only from a contemplation of this variety is it possible for the student to build up a point-of-view, and to arrive at an independent and unbiased conclusion.