37. [THE FORMATION OF VEGETABLE MOULD, THROUGH THE ACTION OF WORMS. With Observations on their Habits]. By Charles Darwin, LL. D., F. R. S. With Illustrations. $1.50.

38. THE CONCEPTS AND THEORIES OF MODERN PHYSICS. By J. B. Stallo. $1.75.

39. THE BRAIN AND ITS FUNCTIONS. By J. Luys. $1.50.

40. [MYTH AND SCIENCE]. By Tito Vignoli. $1.50.

41. DISEASES OF MEMORY: An Essay in the Positive Psychology. By Th. Ribot, author of “Heredity.” $1.50.

42. ANTS, BEES, AND WASPS. A Record of Observations of the Habits of the Social Hymenoptera. By Sir John Lubbock, Bart., F. R. S., D. C. L., LL. D., etc. $2.00.

43. SCIENCE OF POLITICS. By Sheldon Amos. $1.75.

44. ANIMAL INTELLIGENCE. By George J. Romanes. $1.75.

45. MAN BEFORE METALS. By N. Joly, Correspondent of the Institute. With 148 Illustrations. $1.75.

46. THE ORGANS OF SPEECH AND THEIR APPLICATION IN THE FORMATION OF ARTICULATE SOUNDS. By G. H. von Meyer, Professor in Ordinary of Anatomy at the University of Zürich. With 47 Woodcuts. $1.75.