APPENDIX II 467 



Ecology enables one to study the exact environment 

 suited to each plant, its requirements as regards soil, light, 

 heat, moisture, etc. It is now recognised that each plant 

 is characteristic of a particular soil. Of these soils there 

 are six main types, clay or loam, sand, siliceous soils, lime- 

 stone or chalk, peat or humus, saline soil. Hence some 

 knowledge of geology is required for this work. The bearing 

 of ecology upon agriculture and its economic importance 

 will, however, be evident, and therefore the difficulties 

 involved in this study will be the more readily overcome by 

 those who wish to profit materially, as well as mentally, 

 by a knowledge of ecology. 



Under Plant-formations (Introduction, section 9) the 

 main types of plant-formations are briefly described, and 

 the vegetation of any particular district may be assigned to 

 one or more of these. 



Elementary methods of survey are given below. For 

 further details, or a more elaborate method, reference may 

 be made to the author's 'Practical Field Botany,' where 

 survey methods are described, and also the use of instru- 

 ments, etc., for determining the light intensity, temperature, 

 humidity, rainfall, water content, soil texture, with details 

 of how to measure altitude, construct contours, to survey 

 on a detailed plan by the " square " or " gridiron" method 

 for the construction of vegetation maps. It is recom- 

 mended also that ordnance maps be obtained, and each 

 field and other tract numbered and each area examined in 

 detail, one by one, or that plant lists be drawn up, notes be 

 made on the spot, and that each be numbered with the 

 same number as the area on the map. 



The suggestions appended are a compromise between 

 this systematic field to field work, and the old plan of 

 making botanical excursions in the form of haphazard walks 

 to some presumably good locality for plants, when no notes 



