6 CONTENTS. 



PAGE 



VIII. ON CERTAIN ERRORS RESPECTING THE STRUCTURE OF THE HEART 



ATTRIBUTED TO ARISTOTLE 187 



Nature, November 6, 1879. 

 IX. ON THE HYPOTHESIS THAT ANIMALS ARE AUTOMATA, AND ITS 



HISTORY 206 



An Address delivered at the Meeting of the British Associa- 

 tion for the Advancement of Science, at Belfast, 1874. 

 FortnigJdly Review, 1874. 



X. ON SENSATION AND THE UNITY OF STRUCTURE OF THE SENSIF- 



EROUS ORGANS 253 



An Evening Lecture at the Royal Institution, Friday, March 

 7, 1879. Nineteenth Century, 1879. 



XI. EVOLUTION IN BIOLOGY 281 



The Encyclopaedia Britannica, Ninth Edition, vol. viii. 1878. 



\j XII. THE COMING OF AGE OF "THE ORIGIN OF SPECIES" 317 



An Evening Lecture at the Royal Institution, Friday, April 



9, 1880. Nature, 1880. 



XIII. THE CONNECTION OF THE BIOLOGICAL SCIENCES WITH MEDICINE. 333 

 An Address delivered at the Meeting of the International 

 Medical Congress in London, August 9, 1881. 



