68 HEREDITY. 



knowledge at first hand, you may find your minds 

 full of unrest on all these great physiological and 

 philosophical themes. Until you can approach in- 

 telligently the supreme authorities among the spe- 

 cialists on these topics, you may be easily misled 

 by second-rate materialistic writers ; and, therefore, 

 I advise you, as a guide in biological reading, to 

 make an adequate personal study of living tissues. 

 Perhaps it is not improper for me to hint that I fol- 

 low my own advice, as it seems to be taken for granted 

 by certain critics of the bravely anonymous species 

 that this is not the fact. This city has the credit of 

 having produced the best microscope in America, a 

 kind of freak of science and fortune, a one seven cy- 

 fifth objective, and one that perhaps could not now 

 be produced again. Photographs taken by this in- 

 strument I have lately seen commended most highly 

 in the Paris Journal de Micographie (number for 

 November, 1877). That microscope is at the service 

 of this audience ; and I hope to bring to you testi- 

 mony from it again and again in the course of the 

 next few months, as I did last winter in the lectures 

 on Biology. Some time, when the noon can be 

 darkened in this room, I am to give you its work 

 actually in progress on a screen here, so that we shall 

 obtain the facts at first hand. 



It has been hinted here, that Butler and Agassiz 

 are perhaps correct in assuming that the argument 

 for man's immortality, by striking against the possi- 

 bility of the immortality of instinct, is not wrecked, 

 but glorified. For saying precisely what Bishop But- 



