CONTENTS. 



GENERAL INTRODUCTION. 



BY PREST. PORTER, 



ON THE PHYSICAL BASIS OF LIFE. 



PROF. T. H. HUXLEY,. .-*... i 



CORRELATION OF VITAL AND PHYSICAL FORCES. 



PROF. G. F. BARKER, M.D., ... 37 



As REGARDS PROTOPLASM REPLY TO HUXLEY. 



JAMES HUTCHISON STIRLING, ... 73 



ON THE HYPOTHESIS OF EVOLUTION. 



PROF. E. D. COPE, 145 



SCIENTIFIC ADDRESSES. 



ON THE METHODS AND TENDENCIES OF PHYSICAL IN- 

 VESTIGATION, 219 



ON HAZE AND DUST, 234 



ON THE SCIENTIFIC USE OF THE IMAGINATION, . 247 

 PROF. JOHN TYNDALL, LL.D., F.R.S., . 217 



