The majority of the contributors to this manual are citizens of the United Kingdom; of 16, only four are Americans. More than 50 chapters include some 1,400 numbered paragraphs of specific directions for histologic technics. In addition to the detailed procedures, the text includes warnings of pitfalls that may be encountered in the preparation of specimens. A chapter on "the laboratory cultivation of invertebrata" has been added to the present edition; the chapters on tissue culture and staining, which were incorporated in the tenth edition (1937), have been omitted. A minimum of space is devoted to microtomes, and the care and preparation required for the microtome knife, an essential tool in this technical field, is ignored.