1889.] 
369 
[Davis and Wood. 
is to be done, the s} T stematic order embodying the concentrated ex- 
perience of earlier students must be familiar before an examination 
of the order in the state of nature is undertaken. Otherwise the 
observer will fail to apprehend the significant features discovered 
by previous investigators, and will be too much influenced by in- 
dividual and temporary characteristics. Trees might be classified 
according to their height ; growing trees would be separated from 
dead and leafless trunks of the same kind ; small plants would be 
overlooked . 
In the same way there should be some general scheme of geo- 
graphical classification in mind before attempting to describe the 
topographical features of any given region : we shall therefore fol- 
low the scheme based on structure and age, outlined above 1 . Be- 
sides this, there is need of some systematic order of arrangement 
of the members of the scheme, but geographers are not yet agreed 
about the order that shall be followed ; it has therefore been our 
purpose not only to present a systematic description of New Jer- 
sey, but also to illustrate one — the historic — of the many possible 
systems of arrangement that might be followed, in the hope that 
by trial of various systems, a satisfactory one may be at last adopt- 
ed for general use. 
4. The geographic divisions of New Jersey. New Jersey may 
be conveniently divided into three main districts, according to the 
broader features of its structure and topography roughly outlined in 
fig. 1. The crystalline Highlands lie in the north, a region of rugged 
uplands, broken by deep and steep-sided valleys ; associated with 
Kittatinny Valley and mountain on the northwest. The sandy Low- 
lands occupy the south, with monotonous surface of faint relief; 
and between these two there is an intermediate Central plain of 
Cretaceous and Triassic beds, traversed by long, narrow ridges 
of trap. All of these divisions extend beyond the political limits 
of New Jersey. In describing them we shall begin with the oldest 
land surface of which there is any trace still remaining, and take 
up after it as many others as may be found in the order of their 
development. 
*A fuller discussion of this plan of classification is presented in a paper by the senior 
author on “Geographic methods in geologic investigation,” National Geographic Mag- 
azine, T, 1888, 11. 
PROCEEDINGS B. S. N. H. 
VOL. XXIV 
24 
MARCH, 1890 
