CONTENTS 



ii6. Kinds of soils 

 117. The chemical nature of soils 

 (Physiography 



"~ 118. Factors. .... 

 Altitude 



119. Analysis into factors 



120. The barometer 

 Slope 



121. Concept 



122. The clinometer 



123. The trechometer 

 Exposure 



124. Exposure 



125. Surface 



126. Record of physiographic factors 



127. Topography . . . . 

 Biotic Factors 



128. Influence and importance 



129. Animals . . . . . 

 i-?o. Plants . 



PAGE 



79 

 80 



80 



81 

 82 



83 

 83 

 84 



85 

 85 

 86 

 86 



86 

 87 

 87 



METHODS OF HABITAT INVESTIGATION 



131. 88 



Method of Simple Instruments 



132. Choice of stations .88 



133. Time of readings ........ 89 



134. Details of the method 89 



135. Records 91 



Method of Ecograpli Batteries 



I3^> 92 



Expression of Physical Factor Results 



137. The form of results 94 



Factor Records 



138 94 



Factor Curves 



139. Plotting .95 



140. Kinds of curves 96 



141. Combinations of curves ....... 96 



142. The amplitude of curves ....... 98 



Factor Means and Sums 



143 98 



