300 MR. H. H. W. PEARSON ON THE 
Tue Boranr or THE CEYLON Paranas. By Henry Harold 
WELCH PrAnsÓN, B.A., “Frank Smart’ Student of Botany 
at Gonville and Caius College, Cambridge. (Communicated 
by Prof. H. MARSHALL Warp, F.R.S., F.L.S.) 
[Read 20th April, 1899.] 
(With Mar.) 
CONTENTS. 
Page 
Introduction ......... soenan a nenen nana a aana a Kananga naen aana nee 300 
Topography MM 301 
Flora of the Patanas below 4500 ft. (the Uva Patanas) ..................... 303 
Flora of the Patanas above 4500 P. 304 
The Western Boundary of the Patanas ........... sse 305 
The Eastern Boundary of the Patanas ........... ssec 306 
Area'of the Patanas MMMMMMMMMENNNMMM 307 
Theories to account for the Origin of the Patanas ................ eene 307 
Climate of the Patana-area ......................vswaswnnaanunannwwanwa errans 310 
Origin of the Patanas the result of combined effects of Climate and 
Grass-fires MM 314 
General Biological Features of the Flora of the Datanns e. 323 
List Of Plants EEMMMMMMMMMMMEM 332 
Conclusion ..............wwanewswnzanananwanunnuwanunaanwaniww nanu wnwanani www w naamua. 363 
Introduction, 
OnsrRvaATrONS upon the Flora of the Patanas of the Ceylon 
Mountains, an account of which is contained in this paper, were 
made during a visit to Ceylon in the latter half of 1897. The 
purpose of these investigations was to ascertain (i) the probable 
causes whieh have led to the development of these remarkable 
savannah-like expanses in an otherwise forest-covered country ; 
and (ii) to what extent the vegetation of the patanas shows 
adaptations to the peculiar mcological (1) factors under the 
influence of which it has been selected. 
Attempts to settle the first question will be found in these 
pages. The second problem is at present not fully treated of; 
that portion of it, however, which is not here dealt with, and 
which involves an anatomical examination of many of the patana- 
plants, will receive attention in a paper which will follow this 
as soon as possible. Owing to some unaccountable delay in the 
transmission of my collections, and to the pressure of other work 
since they arrived, these results have already been so long 
