LAST LECTURES AT THE MUSEUM. 777 



earth, from the dawn of organic life till now. 

 In his opening lecture he said to his class : 

 " You must learn to look upon fossil forms as 

 the antiquarian looks upon his coins. The 

 remains of animals and plants have the spirit 

 of their time impressed upon them, as strongly 

 as the spirit of the age is impressed upon its 

 architecture, its literature, its coinage. I want 

 you to become so familiar with these forms, 

 that you can read off at a glance their charac- 

 ter and associations." In this spirit his last 

 course was conceived. It was as far-reaching 

 and as clear as usual, nor did his delivery 

 evince failure of strength or of mental power. 

 If he showed in any way the disease which 

 was even then upon him, it was by an over- 

 tension of the nerves, which gave increased 

 fervor to his manner. Every mental effort 

 was, however, succeeded by great physical 

 fatigue. 



At the same time he had undertaken a 

 series of articles in the " Atlantic Monthly," 

 entitled, " Evolution and Permanence of 

 Type." They were to have contained his own 

 convictions regarding the connection between 

 all living beings, upon which his studies had 

 led him to conclusions so different from the 

 philosophy of the day. Of these papers, only 



