PROBLEMS OF LIFE AND 

 REPRODUCTION 



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



Professor of Biology in the University, Cork 

 With Illustrations. 



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 views on such 

 important questions as cytology, reproduction, fertilisation, 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 Weismannian 

 and Lamarckian 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 on "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. 



THE PROBLEM OF AGE, 

 GROWTH, AND DEATH 



A Study of Gytomorphosis 

 Based on Lectures at the Lowell Institute, March 1907 



By CHARLES S. MINOT, LL.D. (Yale, Toronto), D.Sc. (Oxford) 



James Stillman Professor of Comparative Anatomy in the Harvard Medical 



School ; President of the Boston Society of Natural History 



With numerous Illustrations. 



This book deals with a series of important biological problems, yet it is 

 essentially a study of a single phenomenon the increase of the amount of 

 protoplasm. The subjects discussed have received, in part, hitherto relatively 

 little attention from biologists. The results of the author's investigations N 

 extending over thirty years, are therefore of exceptional interest. 



CONTENTS 



Old Age Cytomorphosis : the Cellular Changes of Age Rate ot Growth- 

 Differentiation and Rejuvenation Regeneration and Death The Four Laws 

 of Age Growth of Rabbits Growth of Chickens Death of Protozoa- 

 Longevity of Animals Theory of Life The Age-reckoner Index. 



JOHN MURRAY, ALBEMARLE STREET, W.i 



