HOLE : SOME INDIAN GRASSES AND THEIR CECOLOGY. 29 



knowledge he possesses of Morphology, Anatomy, Systematic Botany, Physiology, and 

 Pathology to the greatest advantage in the solution of problems of practical importance 

 and the successful solution of which moreover constitutes an important part of his daily 

 duties. 



Trained Foresters will find no difficulty in distinguishing and describing the various 

 communities of woodland, a task indeed which forms a part of the "duties of every Working 

 Plans Officer, but this work requires to be undertaken systematically and it is obviously 

 advisable to commence the work with special reference to particular species of greatest 

 importance in all the localities where it occurs. Far more attention also must be paid to 

 the accurate determination and recording of the condition of the factors of the locality 

 which constitute the plant's environment in various habitats. The more detailed and 

 accurate this determination, and the greater the number of the localities in which the observ- 

 ations can be made, the more certainly will the conditions be revealed which are essential 

 for the healthy existence and development of a particular species, and the clearer will be 

 the indication as to the method of treatment which must be adopted if we wish to favour 

 its development and reproduction and to cope with its diseases. It must also be clearly 

 recognised that, in so far as such recorded observations of the condition of environmental 

 factors are correct, they are facts, and as such provide just as satisfactory a basis for a 

 logical conclusion as do experiments. In careful experiments we endeavour to simplify 

 the environment of a plant and in order to test the effect on it of a single factor the latter 

 alone is, as far as possible, allowed to vary and the effect of such variation 

 on the plant is watched. The practical drawback to experiments, however, lies partly in 

 the difficulty experienced in artificially arranging for the isolation of the various factors 

 and partly in the long period of time which is required to obtain accurate information 

 regarding the effect of all the factors of importance capable of effecting the development of 

 a particular plant. Information regarding a single factor alone is of very little value and 

 goes a very little way in explaining the facts observed in the field, inasmuch as in nature 

 several factors are in action together and while one factor may be of primary importance in 

 producing a certain result in one case, in another case its action is masked by the effect of a 

 different factor which, in its turn, has become of primary importance and responsible for 

 the result obtained. 



In recording careful observations regarding the conditions to which a particular plant 

 or type of vegetation is exposed in nature, however, we are doing no more nor less than 

 attempting to read the result of experiments so-to-speak which have been arranged and 

 carried out for us — certain factors have been and are still in operation — the result of this is 

 a certain type of vegetation — and the problem for solution is to answer the query what 

 particular factor or combination of factors from among those in operation is responsible for 

 the result produced'? 



Moreover, it must be remembered that, whereas experiments with woody plants usually 

 require long periods for the production of valuable results, the work of recording the details 



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