vi PEEFACE 



A few chapters have been already published by 

 the Author, but in another connection in the ' Lehr- 

 buch der Philosophic/ 3rd ed., of Father Lehmen, S.I. 

 (published by Father Peter Beck, S.I.). Even these, 

 however, have been partly rewritten and extended. 



My brother in the order, Father E. Wasmann, has 

 been good enough to place at my disposal a contribution 

 from his special sphere of study. Further contributions 

 regarding similar questions he will himself publish 

 in the fourth edition of his work, ' Die Moderne Biologic 

 und die Entwicklungstheorie/ which will shortly 

 appear. 



THE AUTHOR. 



BALKENBURG. 



