X. 



THE EVIDENCE FOR EVOLUTION IN THE HIS- 

 TOEY OP THE EXTINCT MAMMALIA.* 



The subject to which I wish to call your attention this morn- 

 ing requires neither preface nor apology, as it is one with the dis- 

 cussion of which you are perfectly familiar. I bring it before the 

 general session of the Association in view of the fact that you 

 are all familiar with it in a general way, and that it probably in- 

 terests the members of sections who do not pursue the special 

 branch to which it refers, as well as those who do : also, since it 

 has been brought before us in various public addresses for many 

 years, during the meetings of this Association, I thought it might 

 be well to introduce it at this meeting, in order that we might 

 not omit to have all the sides of it presented. 



The interests which are involved in it are large : they are 

 chiefly, however, of a mental and metaphysical character ; they 

 do not refer so much to industrial and practical interests, nor do 

 they involve questions of applied science. They involve, however, 

 questions of opinion, questions of belief, questions which affect 

 human hapj)iness, I venture to say, even more than questions of 

 applied science ; certainly, which affect the happiness of the 

 higher grades of men and women more than food or clothing, be- 

 cause they relate to the states of our mind, explaining as they do 

 the reasons of our relations to our fellow beings, and to all other 

 things by which we are surrounded, and the general system of the 

 forces by which we are controlled. So it has always aj)peared to 

 me : hence I have selected the department of biology for study, 

 and have taken a great interest in this aspect of it. 



The doctrine of evolution, as taught by the biologists of to- 

 day, has several stages or parts of its presentation. First, the 

 foundation princij)le is this : that the species of animals and of 



* An address delivered before the American Association for the Advancement of 

 Science, 1883. 



