160 THE SAVANNAHS OF GUYANA. [Sess. Lxx. 
with its Urwiilder, for the most part unknown; the middle 
part, a strip widening from 30 km. in the east to 100 km. 
in the west, is the flattest part of the diluvium, with only 
few scattered hillocks—in some regions a merely undulating 
plain. It is in this part that we find the savannah through 
the whole breadth of the country,—with the exception of 
the forest-tracts along the rivers, as said before. 
What is the savannah in Guyana? According to the 
native conception, the savannah is an open tract covered 
with low plants, a few trees scattered here and there, and 
surrounded by forest. This conception corresponds very 
well with the description given by Schomburgk, as seen in 
Professor Schimper’s book on Plant-geography, Part IL., page 
327: “ Forests—I have termed them oases—sometimes miles 
across, sometimes of less extent, most frequently with a 
Quart: sand Garden wil Clay. 
sae 7 et A 
—— 77 
PETE Vy W, Yip PHI 
Vertical section through the soil of the Savannah. 
AE 
circular outline, rise out of the savannah like islands from 
the sea,” which gives Professor Schimper himself reason to 
say: “Not a uniform formation, spread over a wide area, 
but a richly differentiated, undulating, park-like country, 
in which different forms of woodland and grassland partake, 
although the latter predominates.” This description, how- 
ever, as well as the native conception, is vague, too vague to 
give a real impression of the savannah. But there is more 
about it in Professor Schimper’s book; on page 360, Part 
IL., we find again: “ It (thorn-woodland) alternates frequently 
with the savannah, and in this case, as in all dry districts, 
edaphic influences are in the first place responsible for the 
change in the character of the vegetation, since savannah 
prevails on a stiffer soil that is superficially wetted by the 
rain, whereas woodland occupies a sandy soil that is very 
permeable to water.” Nothing is more beside the truth than 
this, so far as Guyana is concerned. On the contrary, the 
soil of the savannah in Guyana consists, as shown in annexed 
figure, of three different layers, of which the upper one, 1 to 
