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and give an approximate station, for biological investigation demands far 

 more accurate and complete information. In the development of this 

 work by the Indiana Biological Survey it would be well to issue a circular 

 of instruction to collectors, calling their attention definitely to the proper 

 methoils of work. It would be well in the training of collectors to defin- 

 itely divide their work for the season into two parts, namely, (1) the work 

 of collecting all the plants of their district, together with suitable field 

 notes, and (2) the detailed study of one or more of their most interesting 

 plants. In work of this kind the following points must be especially made 

 out: 



(1.) Mass distribution. It is not sufficient to know that a plant is to be 

 found in this or that part of the county, but it must be known where it 

 occurs in the greatest abundance, and where in the least, and where not 

 at all. The most convenient way to make observations of this kind is to 

 use outline maps as large as possible of the county and upon this jot the 

 occurrence of the plant observed. At the end of the season's work with 

 one or two plants in this fashion, it will be discovered whether one is 

 dealing with a comparatively even distribution throughout the county, or 

 one that follows certain lines, or is restricted to certain localities. It is 

 also easily seen whether the plants mass together in certain places and 

 thin out in others. 



(2.) Topographical distribution. Under this head is to be considered 

 whether plants are inhabitants of uplands, swamps, prairies, etc. If they 

 occur in all situations, which do they seem most to affect and in what 

 respect are their characters modified by such changes of surface? 



(3.) Geological distribution. This must take into consideration the soils 

 upon which the plant grows. This part of the study is one that takes 

 considerable knowledge of geology, for it is not always easy to tell the real 

 nature of a soil, whether it is one in situ, or an artificial soil. For instance, 

 the soil of the valley may not at all represent the disintegration of rocks 

 that border the valley, but may have been transported from some distance. 

 Great care must be taken in the determination of this drifted sojl. 



(4.) The effect of man^s presence. Indiana may be new enough for some- 

 thing to be done in the way of discovering the distribution of most plants 

 before man's invasion. The former distribution of plants, which are now 

 confined to uncultivated areas, should be made out as far as possible. It 

 should also be distinctly noted what effect the presence of man has had 

 upon the occurrence of plants and what plants are able to adapt them- 



