46 ANIMAL ECOLOGY 



the ecologist need have no fear in using such practical 

 methods. In other words, we should consider the 

 future stages of the developing habitat and learn 

 to perceive the evidences which show in which direc- 

 tion development or change is taking place ; or to 

 determine the "orderly sequence of external nature." 

 Not only should the future be considered, but we 

 should strive also to read the record backward and 

 interpret the past in terms of processes now in 

 operation. In this respect the point of view of the 

 geologist who interprets the past in terms of present 

 processes may well merit our attention. To under- 

 stand our habitats they must be studied not only 

 in their length and breadth, but also in depth 

 past and future as they have all three dimen- 

 sions. 



The preceding remarks bear equally well upon 

 observations of the activities of animals in nature, 

 on account of the absence of controlled conditions, 

 for these methods have almost as much significance 

 as the study of the environments themselves ; and 

 equally careful observations and descriptions are 

 essential, if the detailed processes of animal activities 

 and their transformations are to be recorded. 



An experienced naturalist finds that from year to 

 year the amount of notes which he takes increases rap- 

 idly, and in a very direct ratio to the progress which 

 he makes in his study. Good note taking is not a 

 passive process, but one which calls for an alert mind. 

 The prolonged interest which is necessary to secure 

 detailed observations implies such a frame of mind. 



