ERRATA. 

 Page 6, line 21 from top, for " animals " read " mammals." 



9 ,, 20 ,, ,, ,, "but rather" read "as." 



58 9 ,, " (Triebewegung) " read "(Triebbewegung)." 

 ,, 136, lines 7 and 10 for " ues centrale " read "os centrale" 

 ,, 138, line 14 from top, for " princates " read "primates." 

 ,, 169 9 "trees "read "tree," and line 20 for "if "read 

 ,, 178 ,, 1, read "use and natural selection." 

 ,, 181 ,, 5 from top, insert after " Aid " " a factor/' 

 ,, 293, lines 14 and 15 from bottom are transposed. 



