2 THE FOUNDATION OF ECOLOGY 
to formulate a system that will combine the good in each, and at the same 
time eliminate superficial and extreme tendencies. In this connection, it 
becomes necessary to point out to ecologist and physiologist alike that, 
while they have been working on the confines of the same great field, each 
must familiarize himself with the work and methods of the other, before his 
preparation is complete. Both must broaden their horizons, and rearrange 
their views. The ecologist is sadly in need of the more intimate and exact 
methods of the physiologist: the latter must take his experiments into the 
field, and must recognize more fully that function is but the middleman be- 
tween habitat and plant. It seems probable that the final name for the whole 
field will be physiology, although the term ecology has distinct advantages 
of brevity and of meaning. In this event, however, it should be clearly 
recognized that, although the name remains the same, the field has become 
greatly broadened by new viewpoints and new methods. 
HISTORICAL DEVELOPMENT 
3. Geographical distribution. The systematic analysis of the great field 
of ecology is essential to its proper development in the future. A glance 
at its history shows that, while a number of essential points of attack have 
been discovered, only one or two of these have been organized, and that 
there is still an almost entire lack of correlation and coordination between 
these. The earliest and simplest development of the subject was concerned 
with the distribution of plants. This was at first merely an off-shoot of 
taxonomy, and, in spite of the work of Humboldt and Schouw, has per- 
sisted in much of its primitive form to the present time, where it is repre- 
sented by innumerable lists and catalogues. Geographical distribution was 
grounded upon the species, a fact which early caused it to become stereo- 
typed as a statistical study of little value. This tendency was emphasized 
by the general practice of determining distribution for more or less arti- 
ficial areas, and of instituting comparisons between regions or continents 
too little known or too widely remote. The fixed character of the subject 
is conclusively shown by the fact that it still persists in almost the original 
form more than a half century after Grisebach pointed out that the forma- 
tion was the real unit of vegetation, and hence of distribution. 
4. The plant formation. The corner-stone of ecology was laid by Grise- 
bach in 1838 by his recognition of the plant formation as the fundamental 
feature of vegetation. Earlier writers, notably Linné (1737, 1751), Biberg 
(1749), and Hedenberg (1754), had perceived this relation more or less 
clearly, but failed to reduce it to a definite guiding principle. This was a 
natural result of the dominance of descriptive botany in the 18th century, 
