In our review of the first edition of this work we said: "It is destined to occupy a large field of great usefulness because it meets the needs, not only of the medical student, but also of the general scientific student and reader who is interested in the relations of microbes to disease and in their growing importance to agriculture, to sanitation, and to many industries." That our prophecy has been already fulfilled is evidenced by the appearance of this second edition in such a short space of time.
The subject-matter has been brought fully up to date by inclusion of the most important features of the research of the last few years. While bacteriology, in the narrower sense, must be regarded as an all-important branch of medical science, yet one must not forget that this science has done much for the various industries, in many cases having almost created