The passage discusses the increasing relevance of agricultural issues in various sections and affiliated societies' programs, reflecting a broader interest and deeper scientific investigation. It highlights the contributions of non-agricultural professionals, such as biologists, botanists, and ecologists, to agricultural research. The text also reviews Frederico E. Clements' book "Plant Succession: An Analysis of the Development of Vegetation," which provides a comprehensive examination of plant succession, historical summaries, and methods for investigating successional phenomena. The book emphasizes the importance of classifying plant communities using both seral and climax units, and it includes a detailed discussion of past climates and climaxes, making it a valuable resource for students and researchers in plant ecology. Additionally, the passage mentions an experimental study on the tractive resistance of motor delivery wagons, published in the Proceedings of the American Institute of Electrical Engineers, which aimed to determine the horizontal force required to maintain a constant speed on urban roads and pavements.The passage discusses the increasing relevance of agricultural issues in various sections and affiliated societies' programs, reflecting a broader interest and deeper scientific investigation. It highlights the contributions of non-agricultural professionals, such as biologists, botanists, and ecologists, to agricultural research. The text also reviews Frederico E. Clements' book "Plant Succession: An Analysis of the Development of Vegetation," which provides a comprehensive examination of plant succession, historical summaries, and methods for investigating successional phenomena. The book emphasizes the importance of classifying plant communities using both seral and climax units, and it includes a detailed discussion of past climates and climaxes, making it a valuable resource for students and researchers in plant ecology. Additionally, the passage mentions an experimental study on the tractive resistance of motor delivery wagons, published in the Proceedings of the American Institute of Electrical Engineers, which aimed to determine the horizontal force required to maintain a constant speed on urban roads and pavements.