PREFATORY NOTE. 



PART Second of this work covers substantially 

 the same ground as my lectures on Evolution, 

 delivered before the Madison and Plattsburgh Sum- 

 mer Schools and before the Winter School of New 

 Orleans. Indeed, the chief difference between the 

 subject-matter of Part Second, and that of the lec- 

 tures as given at the Summer and Winter Schools, 

 consists in the foot-notes which have been added to 

 the text, and in a more exhaustive treatment of cer- 

 tain topics herein discussed than was possible in the 

 time allotted to them in the lecture hall. 



J. A. ZAHM, C. S. C. 



NOTRE DAME UNIVERSITY, December 18, 1895. 



