128 
REVIEWS. 
ascertain (1) the probable causes which have led to the development 
of these remarkable savannah-like expanses in an otherwise forest- 
covered country ; and (2) to what extent the vegetation of the 
patanas shows adaptations to the peculiar ecological factors under the 
influence of which it has been selected. 7 ’ 
The great bulk of the patanas occur in the Province of Uva at 
elevations from 2,000 to 5,000 feet, but they also cross the central 
ridge of the mountains and occur in small areas in the wet summit 
levels, e.g., at Nuwara Eliya and Horton Plains, and on parts of the 
western slopes of the mountains. A very remarkable feature is the 
sharpness of the boundary between forest and patana—two strides 
will often suffice to pass from one to the other. A critical discussion 
is given of the various theories that have been put forward as to the 
origin of the patanas. Evidence is adduced to show that probably the 
Uva patanas were once covered with a savannah-forest like that still 
existing in the “ Park Country ” to the east. The constantly re¬ 
curring fires started by the graziers, consuming the grasses every year, 
would then gradually reduce the forest area (as is still happening), and 
lay bare the soil to the action of the heavy rain. The trees would 
thus in time be reduced to a few hard-wooded resistent species, such 
as the kahata or patana oak (Careya arborea), and the soil become 
shallower and poorer, till it reached the condition seen on the hills 
north of Bandarawela. Above 4,500 feet, e.g., atHakgalaandNuwara 
Eliya, the climate is wetter ; the patanas, annually fired, have gradually 
spread into this wet region, but here, as in similar places in other 
countries, climatic and other conditions have led to the formation of a 
sour black soil, largely composed of humus. 
The plants of the patanas are exposed to somewhat extreme 
conditions favouring evaporation of water, and show in general the 
structural characters of other dry-country plants {e.g., thick or hairy 
leaves, protective leaf movements, &c.), though by no means to the 
degree that might be expected, even in such places as the exposed 
ridges near Bandarawela. Surprising as it may seem, these “ xero- 
phytic” characters are as well marked in the plants of the “ wet ” 
patanas above 5,000 feet as in those of the “ dry ” patanas. This result 
i s probably to be ascribed to the effects of the coldness of the soil and 
the presence of humus acids in checking absorption of water. An 
interesting parallel is seen in the way in which Australian trees, from 
very dry climates, readily acclimatize themselves in the higher districts 
of Ceylon. 
Interesting details are given of the many structural and other 
peculiarities of the patana plants, and a list of the 289 species of 
flowering plants and ferns found on the patanas. The whole forms a 
valuable contribution to the botany of Ceylon, and a good foundation 
for further work, in which good service may be done by local botanists. 
There is yet a vast amount of investigation required to render 
