T07 



THE CURVING BOUNDARY 



" Could we but know the actual curving boundaries of a few hundreds of our best defined species what a 

 wealth of new generalisations could be drawn from them, and how much new information they would yield 

 concerning the factors which govern distribution in general '. 



" For, irregular as these lines would be, I can but think that they would, in many cases, stand in 

 definite relation to lines of other kinds : to isothermals, to altitudinal contours, to degrees of humidity, 

 to the boundaries of geological formations, the limits of glaciation, the ranges of animals- — especially 

 pollen-bearing insects — to the paths of bird-migration, and finally to the course of human traffic." 

 [Dr. B. L. Robinson's Presidential Address to the Botanical Society of America, Science, Vol. XIV, 

 No. 352 (1901). Quoted in my Presidential Address to the Linnean Society of New South Wales. 

 Vol. XXVI, p. 763 (1901). 1902.] 



I went on to say that " Our results may, for many years, prevent ns from affording 

 satisfactory information in regard to a number of these points, but they are ideals, and 

 should be striven after. I show you to-night a ' curving boundary ' of one of our 

 important species. The idea of graphical representation of range of species occurred 

 to me many years ago, and I have had it in limited use for two or three years. It may 

 proceed simultaneously with the main botanical map, and is, in fact, supplementary 

 to it." 



There was at the time what I may express as a " boom " in the better scientific 

 definition of botanical areas, which has continued to this day, and the most valuable 

 outcome of this has been the inauguration and the building on a firm foundation of the 

 science of ecology. 



In the " Report of the Interstate Conference on Forestry," Perth, W.A., 1917, 

 at p. 13, I made a further reference to the subject, as follows : — 



1. A Botanical or Forest Survey. — First of all let me explain what a curving boundary is by this 

 map [not reproduced]. The use of such a term is an endeavour to replace a vague statement that a tree 

 is found on the Eastern Goldfields, or in the South-west of Western Australia, by a graphic record of where 

 it really occurs. We mark on the map, by a blue cross, or other indication, where a certain kind of tree 

 (a species or variety) has been found, and the more or less curved line, which indicates the outer line (and 

 inner, in certain cases) which joins the intersections of these crosses in the curving boundary. 



In other words, at a particular date, it indicates the territory within which the tree is found. 

 It serves as a basis for a more accurate record, for obviously we are always learning. In a work of this 

 kind the forester and the botanist are mutually helpful, for unless the botanist checks the record the forester 

 may be led to give erroneous estimates of the distribution of a particular tree, and we ought, as regards our 

 Australian trees, to do what we can to dispense with vague generalisations as to the areas and constituents 

 of our forests. While we establish the curving boundary, we concurrently obtain a good deal of 

 i nformation as to the distribution of particular trees within that boundary. 



