1949. Reprinted. 164 pages. No dust jacket. This is an ex-Library book. Red cloth boards with gilt lettering. Expected library inserts, stamps and inscriptions. Foreword written by Sir Frederick Gowland Hopkins. Moderate crinkling and cracking to paper at gutter. Clean pages with noticeable tanning and foxing throughout. Tightly bound with faint thumb marking throughout. Boards have moderate edge-wear with bumping to corners and rubbing to surfaces. Slight crushing and fraying to spine ends. Lettering is darkened. Minor wear marks to boards.