

Progressive Science Series. 



NEW VOLUME, 



PROBLEMS OF LIFE AND REPRODUCTION. 



By MARCUS HARTOG, M.A., D.Sc, 

 Professor of Biology in the University, Cork, 



With Illustrations. Demy %vo. Js. 6d. net. 



[Now Ready. 



This collection of essays is primarily intended for the layman interested in biological 

 problems ; but the professional biologist will find much new or newly-arranged material 

 also. The book not only contains criticisms of certain schools of biological thought but 

 embodies the author's view* to such important questions as cytology, reproduction, fer- 

 tilisation, germination, and heredity. In the essay on " Mitokinetism," a striking new 

 conception of the forces controlling cell-division and of the resemblance of the cell-field to 

 an electrical field is explained. A comparative criticism of the Wejsmannian and Lam- 

 arckian theories of heredity and their modern interpretations will be found most valuable to 

 those who have not the time to follow the voluminous literature on the subject. In the 

 chapter oh " Mechanism and Life," the vitalistic tendency of the Author is manifest, and 

 the differences between living things and machines are discussed in an interesting and 

 illuminating manner. As an admirer of the late Samuel Butler, Professor Hartog treats of 

 the biological works of that ironical and somewhat misunderstood writer with sympathy and 

 insight. The last chapter in the book is an essay on the teaching of nature-study which 

 comes with authority from one having a long experience of University life and teaching. . 



THREE NEW EDITIONS. 



VOLCANOES : Their Structure and Significance. 



By T. G. BONNEY, D.Sc, F. R.S., Emeritus Professor of Geology at University 

 College, London. Third (New and Enlarged) Edition. With numerous 

 Illustrations. Demy 8vo. 6s. net. 



THE INTERPRETATION OF RADIUM. 



By FREDERICK SODDY, M.A., Independent Lecturer in Physical Chemistry 

 and Radioactivity in the University of Glasgow. Third Edition. Revised 

 and Enlarged. With Illustrations. Demy 8vo. 6s. net. 



HE RED I Y« By J. ARTHUR THOMSON, M.A., Regius Pro- 

 fessor of Natural History in the University of Aberdeen. New and 

 Thoroughly Revised Edition, With numerous Illustrations. Demy 8vo. 



gs. net. I 



KNOWLEDGE. — ** May be regarded as the standard work of reference on this subject. 

 As a judicial summary of an exceedingly di fficult and controversial subject it is masterly, 

 while in the matter of clearness of exposition it has no rival." 



JOHN MURRAY, ALBEMARLE STREET, W. 



( xvi ) H 



