two new nitrogen-containing extractives have been found in lower vertebrates: betaine and homarine in lobster muscle, and a guanidine derivative, asterubin, in starfish. More attention is being paid to bacteria, with reports on metabolism, soil microbiology, and fungal biochemistry. The authors thank the contributors, emphasizing the value of expert summaries for researchers. "Solubility of Non-Electrolytes" by Prof. Joel H. Hildebrand is a second edition of a book with a strong thermodynamic background. It covers topics not adequately addressed in standard physical chemistry textbooks. While challenging for some readers, the book provides clear conclusions applicable to real-world cases. The author now questions some previous deductions. "La Espèce" by Prof. L. Cuenot offers a helpful account of species problems, discussing the meaning of species, speciation, and isolation. It includes a survey of genetic phenomena and meiosis. The book is concise, occupying three pages less than the first edition. However, it lacks discussion on gene-complexes, polymorphism, and relative growth problems. The book introduces the concept of "regular solutions," where molecular size and attraction are not required, and thermal agitation leads to random distribution. It discusses Menke's work on liquid structure, London's dipole interaction formula, and Lennard-Jones's force-field theory. Other topics include Langmuir's interfacial energy theory, Bernal and Fowler's water structure research, and Butler's metallic solutions work. The book is stimulating, with a good glossary, bibliography, and index.two new nitrogen-containing extractives have been found in lower vertebrates: betaine and homarine in lobster muscle, and a guanidine derivative, asterubin, in starfish. More attention is being paid to bacteria, with reports on metabolism, soil microbiology, and fungal biochemistry. The authors thank the contributors, emphasizing the value of expert summaries for researchers. "Solubility of Non-Electrolytes" by Prof. Joel H. Hildebrand is a second edition of a book with a strong thermodynamic background. It covers topics not adequately addressed in standard physical chemistry textbooks. While challenging for some readers, the book provides clear conclusions applicable to real-world cases. The author now questions some previous deductions. "La Espèce" by Prof. L. Cuenot offers a helpful account of species problems, discussing the meaning of species, speciation, and isolation. It includes a survey of genetic phenomena and meiosis. The book is concise, occupying three pages less than the first edition. However, it lacks discussion on gene-complexes, polymorphism, and relative growth problems. The book introduces the concept of "regular solutions," where molecular size and attraction are not required, and thermal agitation leads to random distribution. It discusses Menke's work on liquid structure, London's dipole interaction formula, and Lennard-Jones's force-field theory. Other topics include Langmuir's interfacial energy theory, Bernal and Fowler's water structure research, and Butler's metallic solutions work. The book is stimulating, with a good glossary, bibliography, and index.