PREFACE TO THE SECOND EDITION. 



xv 



those who possess the Principles of Biology, in which many 

 references are made to passages in First Principles, would 

 be inconvenienced by the want of correspondence between 

 the numbers of the sections in the original edition and in the 

 new edition, were they without any means of identifying the 

 sections as now numbered. The annexed list, showing which 

 section answers to which in the two editions, will meet the 

 requirement : — 



First Second 

 Edit. Edit. 



81 



82 

 83 

 84 



85 

 86 



87 



§92 

 93 

 94 

 95 

 96 

 97 

 98 

 99 88 



109 149 



110 150 



111 151 



112 152 



113 153 



114 154 



115 155 



116 156 



117 157 



118 158 



119 159 



120 160 



First Second 

 Edit. Edit. 

 §121 §161 



122 162 



123 163 



124 164 



125 165 



126 166 



127 167 



128 168 



129 169 



130 170 



131 171 



132 172 



133 173 



134 174 



135 175 



136 176 

 177 



'183 



144 193 



145 194 



The original stereotype plates have been used wherever 

 it was possible ; and hence the exact correspondence between 

 the two editions in many places, even where adjacent pages 

 are altered. 



London, November, 1867. 



