METHODS 171 



ecologist can, however, quite safely carry a lot of the details 

 in his head and put them on paper at the end of the day. This 

 is a matter of practice, and is a habit worth cultivating, as it 

 saves much time and also makes it possible to do better work 

 in wet weather, when note-taking is awkward. The chief 

 time when it is best to take notes on the spot is when one is 

 trying to prove something definite, since at such times it is 

 very easy to forget the facts that do not agree with one's theories. 

 It usually happens that a certain number of animals are found 

 in odd places which do not fit in with any of the habitats 

 originally listed, and these will necessitate some revision of 

 the habitat-divisions you started with. Again, a number of 

 animals are always occurring accidentally in the wrong habitat, 

 and although they should be recorded carefully, the amount 

 of detail as to their habitat need not be great. Discretion has 

 to be used in this matter. 



II. When a general idea of the distribution of the fauna 

 has been gained, it is advisable to attempt the construction of 

 a rough food-cycle diagram showing the relationships of the 

 species. To do this accurately it is necessary to get the 

 specimens identified, but a rough preliminary idea can be 

 formed without knowing the exact species, although it is useless 

 to publish such a diagram unless backed up by lists of the 

 actual species concerned. It will be found necessary to organise 

 a sort of ring of consulting systematists who are willing to 

 work out material from the various groups of animals. It is a 

 good plan, when sending large numbers of specimens (most of 

 which will probably be quite common ones) to include, if 

 possible, some which seem unusually interesting or rare, 

 since in this way the expert who is working out the material 

 for you will find it more interesting, and will be the more 

 willing to help in the future. ^ For details of methods of 

 collecting and preserving animals the reader may be referred 

 to the British Museum Handbook for Collectors, 1^2 which 

 covers a number of animals, to Ward and Whipple, ^'^ who 

 give excellent directions for most fresh- water animals, and to 

 the various books given in the bibliography of special groups 

 of animals. 



