1960. First Edition. 116 pages. Grey dust jacket over blue cloth. Symposia of the Institute of Biology, Number 9. Contains black and white photographic plates. Pages and plates are lightly tanned and foxed throughout. Binding remains firm. Boards have mild edge wear with slight rubbing to surfaces. Light tanning to spine and edges. Unclipped jacket has moderate edge wear with chips, tears and creasing. Light tanning to spine and edges. Dark rubbing and marking to surfaces, with scuffing to edges.